EVERY BOY HIS OWN MECHANIC BERNARD E. JONES r^ >. \ I \ »* PRKSENTKI) liV EVERY BOY HIS OWN MECHANIC \ USING THE HACK SAW llVork is several inches too high for comprt and efficiency] EVERY BOY HIS OWN MECHANIC BY BERNARD E. JONES I I Editor of "Work" ASSISTED BY A NUMBER OF EXPERTS Illustrated by Sixteen Full-page Plates in Half- tone and Four Hundred Diagrams in the Text New York Funk & Wagnalls Company am JUL i I92S To My Own Boys, Lewis and Anthony PREFACE In this book I have tried to tell boys how to do some of the things I have found them always eager to attempt. I have explained and illustrated for them the everyday tools of the worker in wood and metals, and shown how to use them. I have described a variety of handiwork and useful jobs about the house, and have introduced my readers to a number of mechanical hobbies, such as model electric lighting, wood and metal turning, model locomotive and railway work, fretwork, boat building, toy making, telephone construction and erection, etc., etc. I may say that in almost every chapter I have sought not only to present some interesting work or hobby, but to show my boy readers how to make themselves useful in their homes. Much of the information in this book is " technical," but at the same time it is simple. In other words, I have sought to explain in straightforward sentences the " why and wherefore " of the methods and processes described, believing that the need of the future is for boys and men who understand what they are doing, and why they do it. I have done my best to make every statement easy of comprehension, and to use simple language devoid of unexplained scientific or technical terms. vii Preface It is a pleasure to make a few acknowledgments of help freely rendered me by personal friends. Mr. Henry Greenly, the well-known model engineer, has contributed two chapters on his own subject. Mr. A. Mill ward, a highly skilled amateur mechanic, has explained how to do simple turning in wood and metal. Mr. B. Clements- Henry, electrician, craftsman, author (and ever so many other things besides), has been good enough to go to the trouble of designing an especially simple form of house telephone, and of describing it in the very closest detail. Then there are Mr. R. S, Bowers, who has drawn a number of the best illustrations in the book, and Mr. J. G. Ross — a technical chemist — who has kindly revised the chapter on silvering glass. And I certainly must not forget to thank my boy friend Ronald Gaze, and my son, Lewis R. Jones, both of whom took pains in posing for a number of the photographic plates. Still further acknowledg- ments are made in certain of the chapters. May my young readers find delight in putting into practice the information which I give them in the pages of this book. B. E. J. CONTENTS How TO Use Woodworking Tools Making and Using Various Cements Erecting Electric Lamps and Bells The Hektograph Copier : How To Make and Use It Inserting a Window Pane Various Workshop Metals : How to Identify and Work Them ..... Making Picture Frames .... How to Use Metalworking Tools Glue : How to Prepare and Use It Electric Batteries and How to Make Them « Soldering ..... Making Simple Wooden Toys . Painting, Enamelling, and Staining Fretwork in Wood . Cleaning and Adjusting a Bicycle Gilding with Gold Leaf and Gold Paint Making Mortise-and-Tenon Joints Building a Cardboard Model L. & Locomotive Turning Wood in the Lathe How TO Mount Pictures . Some Easy Things to Make in Wood ix S.W.R. Express 1 35 41 65 70 74 82 94 105 111 125 138 153 161 172 190 194 204 219 231 237 Contents Etching a Name on Metal Varnishing and Polishing Making Hutches .... Waterproofing Tents, Ground Sheets and Making Dovetail Joints in Wood Turning Metal in the Lathe . Fretwork in Metal and Ivory Building a Dog Kennel Laying the Rails for a Model Railway Building a 10-ft. Flat-bottomed Rowing A Model Aeroplane that Flies Nails and Screws .... Some Useful Jobs about the House A Word on Wood .... A Practical Home-made Telephone . Index PAGE . 245 . 250 . 255 Garments 268 . 270 . 281 . 285 . 289 . 298 Boat . 307 . 319 . 328 . 330 . 340 . 343 . 367 LIST OF PLATES Using the Hack Saw rCHES Rip-sawing Tool Sharpening Planing .... Using Screwdrivers . Wiring Electric Lamps and S\v: Picture Framing Filing at the Vice Soldering .... Easy Toy Making Bicycle Cleaning and Adjusting Model Locomotive, Station and Signals Some Easy Things to Make in Wood Dovetailing ..... Model Railways .... Building Model Aeroplanes Frontispiece^ FACING PAGE 8^* 16*^ 80^ 104«^ 128*^ 144»^ 208^^ 240^ 272^ 304'' 320 -' EVERY BOY HIS OWN MECHANIC HOW TO USE WOODWORKING TOOLS The Bench. — The average boy mechanic is in my mind as I write. He will be interested in a variety of mechanical work, of which wood-working will be just one branch, and possibly he may have no convenience for a bench of his own, in which case perhaps he can use another's or can adapt a strong table to his pur- pose. Table benches are use- ful for light work, particularly so if there are side and cross rails near the floor, as Fig. 1. — Kitchen Table fitted up as Wood- working Bench these add tremendously to the rigidity of the construction. The average kitchen table is not rigid enough to withstand the stresses set up by planing, but if it is used in the corner of a room or against a wall, and the planing is always done towards the wall, the table may be made to serve very well. B I Every Boy His Own Mechanic 41HSiaB] Fig. 2.— Iron Bench Screw Its chief lack will very quickly be discovered. There is no vice in which to hold pieces of wood for chiselling, tenon-sawing, etc., and the worker will not long be satisfied without one. Fortunately, a vice can be added to a kitchen table at small expense {see Fig. 1). Nearly every tool catalogue shows both wood and iron bench screws, both of them fairly cheap, and the iron ones {see Fig. 2) can be rapidly converted into efficient vices. Should the table-top overlap the side rail, as it almost certainly will, first screw on a piece of wood as wide as the table rail, of any suitable length, say from 6 in. to 12 in., and of such a thickness that its outer face comes flush with the edge of the table-top. If one piece of wood is not thick enough, use two or three, and screw all together. For the cheek of the vice you will need a piece of good hard stuff of any convenient width, say, 6 in. wide and roughly 18 in. long. The iron screw will vary in diameter, about eight sizes between ye ^^• and If in. inclusive being obtainable. You will need a centrebit that will cut a hole through which the screw will easily pass. With this bit cut a ^^^- ^--^^"'^^ ""''' "'^ ^^^^^'° "^'"^ hole in the vice cheek, and right through the thickened rail of the table. On the screw is a nut which must be removed and screwed on the back of the rail in such a 2 How to Use Woodworking Tools position that the bench screw engages with it freely. There is also a collar which in the simplest form of con- struction is split {see Fig. 2). In attaching the screw to the vice cheek, it is pushed in as far as it will go, the split collar placed in position so as to engage in a recess cut in the screw, and the collar attached to the cheek with half a dozen small screws. On turning the screw by means of the lever handle, the vice cheek is moved to and fro, but owing to its length it will not move per- fectly parallel with the table unless a "runner" is fitted to it. Now, B in Fig. 1 shows such a runner, and a is the vice cheek, and Fig. 3 is another view of it. The runner may be of 1 in. stuff by 1| in. deep, or any size similar, and 1 foot or more in length, tenoned into the end of the vice cheek, as shown in Fig. 4, it being Fig. 4.-Run^cnoned into made a tight fit, and screwed ^**'® Check from the front as indicated in the other views. A long, narrow box in which the runner slides easily is next made, but it is not fitted into position until careful testing has shown what its exact position should be. The presence of the runner, which should fit its box well, but not tightly, will ensure that the vice cheek is kept parallel with the side of the table when the screw handle is worked. Full details of the arrangement, which you can easily follow, are given in Fig. 5. Two details of the illustrations need a word of comment. In Fig. 3 is shown a planing board which protects the surface of the table, and in which two little mortises have 3 Every Boy His Own Mechanic been cut. Two pieces of wood (shown suspended over the holes) fit the holes tightly and can be slightly raised when required to form stops against which the work will be held for planing. The other detail is the little L-iron pieces screwed to the feet of the table legs in Fig. 1, and PACT Of TA^LL-TOP ■ ^ INNER VICt-CHLDC •• fA.CE. OWUlDs BiaiiOtPACKiyiG-PllCL TOEHABLLBCDCTOttFDOD X MUn BL FLUSH V/HH EtXiL / OF X\6lL-TOP[AUT-a ^.-^ - FU/JH WITH FACl a TABLL-UG J ^^^^Vj^^^^^^^^K 1 ^^ t RAILS OF ^,J\Z^'-^^'^^>^^Z^ ^^ s ^ 6C?XHaD]MGA5a)«NEjL HOfnOOE-TIHOllEDIJiTO [A^AT4 1 if jlf TOP EDGE MUST EL ^ fLUfHWnHTi9P0fTABLL 1 UG a TAfcEL Fig. 5.— Constructional Details of Kitchen -Table Bench also to the floor to render the table immovable when doing heavy work such as planing. Of course, if you can afford to buy just the bench you want, there are many excellent designs available. Those with drawers or cupboards {see Fig. 6) are first-rate, and full details of construction are shown on the opposite page. The great advantage of a strongly-built "portable" bench is that the whole construction is held rigidly by means of 4 4'6"- 1'6'. A:^ 3>i iV I L^ 2isq Top of Leg Dovetailed to Rail Front and End Elevations of Bench Sketch of Complete Bench as in use BENCH TOP SCREW Section showing how Vice is fitted Arrangement of Drawer Runners, etc. Fig. 6. — Sketch and Working Drawings of Bench with Shelf and Tool Drawers Every Boy His Own Mechanic wedges which can be easily knocked out when it is re- quired to take the bench to pieces for removal. The pin- board on the front of some benches is for the purpose of supporting long boards, one end of which will be held in the vice and the other supported on a wooden peg pushed into one of the holes at a suitable height. Tools. — Sawing, planing and chiselling make up the bulk of woodworking, and I advise you to buy just the few tools that are essential and not to bother your head or empty your pocket by obtaining a fitted tool chest. Most of the tool boxes I have seen contain a number of tools that are seldom required, and only the best of these fitted boxes contain tools of really high quality. You can do a lot of things with just a few simple tools of average size and of good quality, kept in thorough order, and used with as much care and skill as you can muster. I am not going to bother you with a long list of the tools required (I show two groups of them in Figs. 7 and 7a), except to say that you will need a saw, a plane, two or three chisels, and the everyday tools that most households possess, such as a hammer, bradawl, gimlet, screwdriver, 2-ft. rule, etc. One or two other tools that would be extremely useful will be referred to as the occasion for their employment arises. The number of tools required depends so much upon what you want to make and upon the size and condition of the wood which you can get for the purpose. For example, if you can obtain at a local sawmill or carpenter's shop wood of any convenient length, width, and thickness accurately cut and properly planed, there is no need to buy a hand saw or a jack plane, extremely useful though those tools are, and you 6 Haad Saw Tenon Saw Wooden Spokeshave Brace Fig. 7. — A group of fourteen of the Woodworker's chief Tools and Appliances Every Boy His Own Mechanic can keep the money by you until you take in hand an ambitious job where the tools mentioned cannot easily be dispensed with. Under such conditions as I have named a good tenon saw would answer most purposes, but don't get a cheap one, and don't buy one at a *' clearance sale " unless you get with it a guarantee that it is by a good maker. The hand saw is used for severing a board, and may be used either with or across the grain, for which reason it consists of a single piece of fine steel slightly tapered in thickness towards the back so that it works sweetly in the cut or kerf. The tenon saw is used chiefly in shaping work in the making of joints and for other accurate cutting of a finer and slighter nature than that which is generally accomplished with the hand saw. It has a thinner blade than the last mentioned, and very much finer teeth, and to prevent its twisting or buckling when in use it is strengthened with a back of brass or iron, as shown in Fig. 7. Some tenon saws have a hinged back, which can be pushed out of the way to allow of the saw being used as a hand saw, but I have not yet seen a tool of fine quality made in this way. A small brass-backed dovetail saw will be found useful. Saws for cutting small curves are the turn saw, compass saw, and keyhole saw. How to Use a Saw. — Let our first attempt at wood- working be the sawing of a piece of board accurately to a line. The saw is to be started and maintained at work so as to make a neat cut at right angles to the face of the timber. Plenty of boys wonder why they cannot saw off a piece of wood with a perfectly straight and square edge. They get an edge which alters in its angle at every half 8 How to Use Woodworking Tools inch, and in trying to correct it they produce another edge just as bad and run the risk of making the work too short for the purpose intended. The reason is that they c:3i Marking Awl and Knife Twist Bit Centrebit Sliding Bevel Twist Gimlet Fig. 7A. — Another group of fourteen of the Woodworker's chief Tools and Appliances do not adopt the proper position. One of the photo- graphic plates in this book shows the position for ensuring that the saw is cutting square to the face of the work. Every Boy His Own Mechanic Look at it closely, and you will discover the secret of accurate cutting. You will note that the saw, the fore- arm, and the right eye are in one vertical plane, and if you accustom yourself to working in this position you will soon get into the habit of square cutting. Every now and then you can test the accuracy by means of a try-square (Fig. 8). The saw must be held as illustrated in the photograph from the very first cut to the last. At starting it is guided to the spot re- quired by the thumb- nail of the left hand (Fig. 9), and the first stroke is a short up- stroke which just abrades the edge of the work and makes an easy path for the down stroke, which is the real cutting stroke. On the return upstroke take all pressure off the saw, as the teeth are so shaped that each one removes a little scraping when the saw is thrust forward, but has only a slight bruising action when drawn backwards in the cut. The carpenter who presses the saw into the work on the back stroke soon dulls his tool. Even on the down- stroke do not press too heavily, and do not grip the ID Fig. 8. -Testing Accuracy of Sawing by means of Try-square How to Use Woodworking Tools handle too tightly or the vibration will soon cramp the fingers and tire the muscles of the arm. To keep the saw to the line, the handle is very slightly lowered occasionally, the eye observing that it is following the path intended. But in taking pains to keep to the line do not " lay " the saw too much, as you will then be in effect increasing the thickness of the stuff and making the job a harder one. But, as I have said, unless you lay the saw to some ex- tent, you cannot be sure of following the line. In rip-sawing — cutting with the grain — you will need to support the work at both ends, whilst for cutting across the grain, it is usual for part of the plank to overhang the box or sawing stool. In both kinds of sawing the parts requiring the most care are at the begin- ning and the end of the cut, the first because accuracy and neatness depend upon it, and the second because without careful work it is easy to break off the partly-severed piece and leave an ugly splinter. Thus you need to go slowly and gently when approaching the end of the cut, and you or a helper must support the work until the saw has com- pleted the cut. The method of starting the cut is the same II Fig. 9.— Starting a Saw Cut Every Boy His Own Mechanic for both rip-sawing and cross-cutting. In your early experiments, and especially if the saw is not in good condition, the tool may become nipped when well into the wood. This is because you have run the saw slightly out of the straight, with a consequent tendency to bend it in its width. You can overcome the trouble, as a rule, by wedging open the cut with a chisel, or by starting the cut at the other end of the board. Fig. 11.— Bench Hook Fig. 10. — Cross Halving Using a Tenon Saw. — Tenon - sawing needs to be much more accurately done than hand-sawing. You use the tenon saw in preparing the ends of two pieces of wood to be joined together, and any inaccuracy will probably betray itself in the finished job. But with a little care and using a good sharp saw you will rapidly overcome any initial difficulty, and will soon learn to make a straight square cut. It is held and started in the same way, but otherwise is used differently, as it is frequently necessary to cut a kerf the whole width of the board, and the " laying " of the saw condemned in the case of the hand saw is now unavoidable. In tenon-sawing it is 12 How to Use Woodworking Tools often necessary to grip the work in the bench screw, and alter its position from time to time so that all saw cuts can be made in the vertical plane. When making a halved joint {see Fig. 10) the tenon saw is the chief tool used, and the work is generally held, not in the vice, but in a simple device called a bench hook (Fig. 11), which is used as illustrated in Fig. 12. This bench hook is a piece of wood of any suitable dimen- sions with nar- rower pieces screwed across its ends, one on one face and one on the other. The left hand holds it and the work which it sup- ports firmly on the bench, the Fig. 12. — Sawing Halved Joint in Bench Hook underneath strip which abuts against the edge of the bench top preventing it from slipping. However well a joint may be set out on the work, it is quite easy to spoil it in cutting by inattention to one im- portant point. It must always be remembered that a saw wastes an amount of wood of a width equivalent to the thickness of the saw measured across the face of the teeth {see end view, Fig. 13). To give the saw clearance, 13 Every Boy His Own Mechanic alternate teeth are bent or hammered sideways, the re- mainder being bent in the opposite direction. The result of this " set " is that a saw cut or kerf is of appreciable width, quite enough in itself to make all the difference between a good-fitting and a bad-fitting joint. For example, two pieces of wood sawn off a length of stuff measuring 3 in. by 1 in. are to be halved together to make a cross. It is quite obvious that in each piece must be cut a recess measuring exactly 3 in. wide and | in. deep. Two lines are scratched or pencilled on by the aid of the try square at right angles to the edges of each piece, and exactly 3 in. apart. These lines are continued across the edges of the stuff, also by means of the try square, and a line midway between the two faces is drawn Fig. 13. upon the edges by means of a marking gauge v"ew°of i^^S- '^^)' To avoid mistakes in cutting, pencil a Saw heavy cross on the face and edges of the part Teeth, showing that IS to bc rcmovcd, and next make the cuts with the tenon saw. If both cuts are made exactly on the lines, half of each cut will be in the body of the work and half in the waste that is to be re- moved, and when the recess is finished, you will find that you will have a loose fit, the recess being too wide by the width of the saw across the teeth. If the cuts are made outside the lines, the greater will be the discrepancy. You will take care, then, to make the cuts inside of and touching the lines. That is, in joint making saw-cuts must always be made in the waste, whilst in cutting off a piece that is required to be of precise length the cut must also come inside the line, so that the piece is not H How to Use Woodworking Tools robbed of an amount equal to the thickness of the saw teeth. Planes. — Everybody recognises a plane when he sees it. The body is of wood or metal, and in it is held a cutter or chisel at such an angle that it takes a shaving off the wood when the plane is pushed forward. Long planes are used for making the work flat and true, short ones for bringing the work to a smooth surface. Trying or trueing planes are among the longest in general employ- ment ; next comes the jack plane, the most popular of all; and the small plane is the smoothing plane. In wooden planes the cutter is held by a wedge. Modern planes are often of iron or steel, and the cutter is held in position and is adjusted by means of a simple screw. It is of not much use telling you how to use a plane unless first of all you know how to take it apart, sharpen the cutter, replace the iron wedge, and adjust it to get a good result. If you have an up-to-date metal plane, the method of removing the cutter will be too obvious to require description here. In the case of a wooden plane, either 15 Fig. 14. -Striking Plane on Bench to loosen the Wedge Every Boy His Own Mechanic jack or smoothing, the cutter can only be removed by first loosening the wooden wedge. Take a jack plane in your hands as in Fig. 14^ which shows the tool upside down. The wooden part is held by the left hand, while the right holds the wedge and cutter. Bring the plane down smartly on the top of the bench, and this will have the effect of releasing the wedge, and allowing the iron to be withdrawn ; or, if you prefer^ hold the plane as in Fig. 16. — Hammer- stop or Striking- button in Plane Fig. 15. — Striking Plane with Hammer to loosen the Wedge Fig. 15, the right side up, the fingers of the left hand reaching to its face, and the thumb being inserted in the opening (which is known as the throat )j and press on the face of the iron. Take the hammer in the right hand and give two or three smart knocks on the top of the plane in front of the left hand. This is a more gradual method of loosening the wedge, but the hammer is liable to mark the plane unless the latter has what is known as a "hammer stop" let into it. Fig. 16 shows such a stop in section. It is simply a plug of hard wood with a i6 How to Use Woodworking Tools rounded top glued into a hole that has been bored in the plane stock for its reception. This plug takes the hammer blows and prevents disfigurement. The plane is now in three parts — the stock, the wedge, and the cutting iron (Fig. 17). Now, the last- mentioned is itself in two parts {see Fig. 18) ; one of these is simply a wide chisel with its corners very Fig. 17.— Stock and Wedge of Jack Plane Fig. 18. — Plane Cutter and Cap- or Break-Iron slightly rounded off so as to prevent the cutter dig- ging into the wood and leaving ridges. Screwed to the cutter is the cap-iron, or break-iron, which does not reach quite to the cutting edge, and which must be removed before the cutter can be sharpened. If c 17 Every Boy His Own Mechanic you look at Fig. 19 you will see how a plane does its work. The cutter is projecting slightly from the face or sole, and pares a shaving from the wood over which the plane is pushed. This shaving enters the plane through a narrow mouth where it meets with the rounded end or face of the cap-iron, which breaks its stiffness and gives it a curved shape, so that as the plane continues to work the shaving easily passes out through the wide throat. In an old plane reduced by much wear the mouth has be- come wider than it was originally, and the shaving tends to split away from the work because there is not enough wood im- mediately in front of the cutter to hold the grain down. Very often an old tool is made serviceable again by gluing in a block across its face so as to reduce the width of the mouth. To remove the cap-iron from the cutter is simply a matter of undoing a screw. Now we have the cutter to sharpen and set, and the work will afford us an example of how all woodworking chisels are prepared for their work. The hand chisel, for example, is sharpened and set in almost exactly the same way as a plane iron, and the one explanation will do for both of the tools. There is just one difference. The edge of a chisel is straight, i8 Fig. 19. — " Cut-away " view of Jack Plane, showing the working principle How to Use Woodworking Tools whilst that of a plane cutter is very slightly curved for a reason already explained. Sharpening Plane Irons and Chisels. — When you receive a new plane, you may find that the edge of the cutter has been ground but has not been sharpened. Such a cutter may be sharpened many times for every once that it will require to be ground. The grinding angle is about 20°, and the sharpening angle about 30°, Fig. 20.— End of Chisel, showing Grinding Angle (A) and Sharpening or Setting Angle (B) Fig. 20a.— Showing how Edge of Chisel is spoilt by Bad Setting ; note the Rounded Angle Fig. 21. — Cross -sec- tion through Oilstone and its Case ; the Rubber Plugs hold Case to the Bench as indicated in Fig. 20. You can go on resharpening the cutter from time to time until much of the grinding angle has been worn away. Then the cutter must be taken to somebody who has a grindstone and a new bevel of 20° ground on it. I won't trouble you with the grind- ing, as not many boys have a grindstone of their own, but the sharpening for which an oilstone is necessary is an operation which you must master. The professional woodworker gets easier and better results with edge tools very largely because he thoroughly understands how to IQ Every Boy His Own Mechanic keep them in order, whereas a great many amateurs fail in this respect. First you will need a good oilstone, and preferably it should have a case (Fig. 21). If you have one already in the house make that do. If you propose to buy a new one, ask for a Washita, or an Arkansas, both of them natural stones, or for a medium grade India stone, which is an Fig. 22. — Sharpening or Setting a Chisel ; the Handle is here shown a trifle too high artificial product of a reliable quality. Have some sweet oil in a can handy on the bench and grip the cutter or chisel with the right hand, as shown in Fig. 22. Place the fingers of the left hand lower down the tool so as to provide pressure, whilst the right hand will see that the proper angle (about 30°) is kept. This is where difficulty will come in at first. The right hand will not move to and fro quite parallel with the face of the stone, 20 How to Use Woodworking Tools and the sharpened face of the cutter will have a rounded instead of a perfectly straight surface {see Fig. 20a), but that is a matter which care and practice will put right. Anoint the stone with oil and start the rubbing. I expect it will take you at least ten minutes at first to get anything like a good edge on a blunt-ground chisel. Your arms will ache and your hands be cramped, and you will be tempted to leave off before you ought to and make do — . . : ;-p«i Fig. 23. — Diagram indicating Side Movement in Sharpening a Plane Gutter Fig. 24.— Rounded Edge of Smoothing Plane Cutter (A) and Jack Plane Cutter (B) with an inferior edge. If you fall to the temptation you will work far harder at a later stage than ought to be necessary. You will waste time, and will fail to pro- duce that proper, cleanly-cut surface which should be the pride of every craftsman. Keep a chisel moving to and fro in the same path, but a plane cutter should be moved slightly from side to side {see Fig. 23) to produce the slight roundness of edge of which I have already spoken, a (Fig. 24) shows the edge of a smoothing plane cutter, and B that of a jack plane cutter. In the course of a few minutes you will see that the 21 Every Boy His Own Mechanic rubbing is beginning to tell, but do not try the edge with your finger, for obvious reasons ; the eye alone will tell you when the bluntness has been rubbed off. Wipe the tool when it has reached this stage on a piece of rag, and notice that on the opposite face of the chisel a wire edge has been turned up. This is removed by placing the tool perfectly flat on the oilstone — avoid the least sus- picion of an angle — and giving one or two gentle rubs. The cutter should now be in good condition, but can be made even keener by stropping it on a piece of leather into which has been rubbed a mixture of tallow and crocus powder. Sharpening Gouges. — Let me drop a note in here on the method of sharpening a gouge, which, after all, is only a chisel of curved section. There are two Fig. 25.— Sharpening Gouge on sorts of gougcs as there are two ^*°°* sorts of chisels, the firmer and the paring gouge, the firmer having the bevel ground on the outside, and the paring gouge having an inside bevel. The firmer gouge is sharpened in the same way as an ordinary chisel except that the tool must be kept turning to and fro as the curve demands (Fig, 25). A wire edge will be turned up as before, and this must be removed on an oilstone slip of curved section on which the gouge will lie in intimate contact while being gently rubbed. The paring gouge must be sharpened from the inside on an oilstone slip, it being customary to hold the tool still and move the slip to and fro, taking great care that 22 How to Use Woodworking Tools the correct angle is maintained. To remove the wire edge in this case, place the gouge flat on an oilstone and give a gentle rub or two whilst slightly revolving the tool, in this case, also, taking the very greatest care not to produce an opposing bevel. Gouges should be well stropped. Re - assemblin£f the Plane. — Now we can get back to the plane. The cutter has been sharpened and stropped to a wonder- ful keenness, and we wish to get it back into the stock and see what it can do. Holding the cutter in one hand and the cap-iron in the other, slide them to- gether until the cutting edge projects by, say, two or three thirty-seconds of an inch. Then tighten up the screw, and place the double iron in the throat of the plane. The thumb of the left hand will hold the cutter in position until the wedge can be pushed in firmly. Lean the back end of the plane on the edge of the bench in such a position {see Fig. 26) that you can sight down the sole or face and observe the exact amount by which the cutter projects. A very slight projection is all that is required. Give the wedge a tap or two with the hammer, and the cutter will 23 Fig. 26.— Sighting along Sole of Plane for Projection of Cutter Every Boy His Own Mechanic be fixed. Again sight down the face, and if the cutter projects too far give the front of the plane a light blow with the hammer and again give a tap on the wedge. On the other hand, if there is not enough projection, give the cutter a gentle tap from the back, all the while sighting down the sole to see you don't over-do it. Using a Plane. — You will be anxious to try the plane. The method of holding it in the case of a jack plane or other large tool will be quite ob- vious from Fig. 27. The handle, called a toat, is grasped by the right hand, while the left hand bridges the front, the thumb being on the near side and the four fingers on the other side, as illus- trated. Fig. 27. — How to hold the Jack Plane A smoothing plane has no handle and needs to be grasped firmly at the back by the right hand, as in Fig. 28, whilst the left is passed right round the front end, the thumb lying on top of the plane, and the fingers extending to the far side. The jack plane should be given a straightforward thrust, each stroke being as long as the work demands or 24 PLANING Holding a Jack Plane Position when Planing Testing Planed Wood Across the Grain Sighting a Piece of Planed Wood for Straightness How to Use Woodworking Tools as the craftsman can make it. Just as the cut starts, the left hand presses down the front of the plane, but gradually this pressure is released as the stroke nears its end. You will need to hold yourself correctly. Stand- ing in front of the bench, the right foot will point towards it whilst the left will be parallel to it, the direction of planing being towards the left. If the tool fails to take off a thin even shaving and if you are convinced that it is in good order, you had better make quite sure that you are not working against the grain, as this has the effect of splitting off the shavings as they are formed. Should it happen, reverse the work. Of course, wood with a very curly grain is not easily planed ; indeed, sometimes planing has to be replaced by the use of a woodworker's scraper, which is a piece of flat steel with a keen but turned-over edge. Much the same advice applies to the manipulation of the smoothing plane. It must be lifted sharply on reaching the end of the stroke so as not to leave a mark ; and it is unwise to attempt at first to plane end grain 25 Fig. 28. — How to hold the Smoothing Plane Every Boy His Own Mechanic with it, although in cases where this must be done it is usual to pare away the extreme end of the edge that is to be planed ; another dodge is to clamp on a piece of waste stuff so that if the grain of the wood is split by the plane the damage will occur to the waste and not to the work. The Scraper. — Not many amateurs can use this simple tool successfully. I mention it because it is an alternative to the plane when working on curly-grain woods, whilst on other woods it is used after the smoothing plane. Fig. 29 shows the principle on which it cuts, and Fig. 30 the tool itself. The cutting edges are a b and c D, and the rounded corners should be noted. It is used as in Fig. 31. the scraper being pushed away from the worker, as from a to b, but occasionally it is manipu- lated in the reverse direction. The scraper must have been ground with square edges, and these should be brought into perfect condition by rubbing on the oilstone in the position shown by Fig. 32, afterwards placing it flat on the stone (as in Fig. 33) and removing any burr. Then rub with a polished gouge (as in Fig. 34) till the sides are polished; again squaring the edge on the stone should any burr be caused. The next proceeding is to turn up a very fine burr (this is much exaggerated in the diagram, Fig. 29), to do which the scraper is laid flat on the edge of the bench, as in Fig. 35, and a polished gouge or any similar smooth steel tool used in an upright position is lightly pressed about twice along the edge at right angles to the flat sides of the scraper. You will probably need to make a good many attempts before you succeed (re- setting the tool on the oilstone every time), but success 26 How to Use Woodworking Tools is worth while, because the scraper is a wonderful tool- a real cutting and not a scraping tool — and its " sweet use gives a lot of pleasure. Fig, 33 Fig. 29 Fig. 29. — Working Principle of Woodworker's Scraper Figs. 30 and 31. — Scraper and how to hold it Figs. 32 to 35. — Four Stages in sharpening the Scraper Chisels. — The boy mechanic will show his excellence as a carpenter by his skill in the use of a chisel. Every- body knows the shape of the ordinary chisel, and I will only say that the long thin chisel is used for paring, and a shorter one, the firmer chisel, for making mortises, etc., 27 Every Boy His Own Mechanic for which purpose it is driven with a mallet. Carpenters have a very thick chisel known as a mortise chisel with which to lever chips out of slots. Ordinary chisels vary in width from -^^ in. to 2 in., and they are sharpened exactly as a plane iron {see p. 19), except that the edge forms a straight line, whereas in a plane iron the corners are rounded off. On a grind- stone a chisel is ground to an angle of 20° or 25° (the latter for hard wood), but this is not the angle ad- hered to when the chisel is placed on the oilstone. Some- thing a trifle blunter is aimed at, so as to give the edge greater strength ; thus the set or sharpened edge forms an angle of about 30° to 35°. Fig. 20, on page 19, shows the working end of a chisel, and it will be seen from this that the tool can be repeatedly rubbed up on an oilstone until most of the ground bevel has been worn away. Then regrinding on a grindstone becomes necessary. I believe the great trouble in using chisels is the diffi- culty of making and keeping them sharp. Beginners don't seem to be able to get a straight bevel. They get, 28 Fig. 36. — Paring on the Slant How to Use Woodworking Tools instead of the flat facet, a rounded face surface with which sweet cutting is impossible {seeFig. 20a). Practice sharp- ening the tool until you can do it really well, and the actual use of the chisel will then be a much simpler matter. A chisel is used for two purposes — paring by hand and chipping when driven by a mallet. By the way, don't hit the handle of a chisel ^*-t- with a hammer ; use a ' wooden mallet. Just be- cause a chisel is sharp^, and you like to swing your mallet, do not be tempted to take out deep chips. It is so easy to overstep the mark, and also to splinter the work on the side farthest from you. The best practice is to remove a chunk of wood by means of reason- ably thin parings, and Fig. 37.-Vertical Paring of Corner paring may be done horizontally or vertically, which- ever you find the more convenient. Sometimes paring is done on the slant, but, of course, do not try to pare against the grain, or you may split the work. In other words, when paring off a corner {see Fig. 36), start from the side, and cut slantwise across the grain, the wood being held upright in the vice so that the pared surface is approximately level. You can pare off a corner by having the wood quite flat on a bench, and here again you must start at the side of the wood 29 Every Boy His Own Mechanic and work towards the end {see Fig. 37), as otherwise the chisel may easily dig in and split the work down the grain when the chisel nears the side. An experienced wood- worker would use the chisel in a job of this sort with a to-and-fro motion, so that the edge of the tool enters the work much as would the blade of a knife. If you take up a stout piece of wood, and try to remove a thick chip from the end with a knife you will almost unconsciously give the knife a slight movement lengthwise as well as forwards so as to facilitate the cut- ting action. The same principle frequently applies in using a chisel. Try to sharpen a thick pencil with a chisel and you will get the idea at once. Makingf a Halved Joint. — There is a common joint which will afford us some practice in using a chisel. It is the halved joint (Fig. 10, on page 12) to which I remember my first introduction was in the making of a toy sword, in which it is customary to sink the crosspiece flush with the handle. By means of a square two lines are set out on the face of each piece, the distance between these lines being the width of the stuff. On both sides of each piece the lines already drawn should be squared over (Fig. 38), and at half the thickness^ there is drawn a line with a gauge Fig. 38. — Setting-out and Working Gross- halved Joint How to Use Woodworking Tools parallel with the face of the work ; thus both pieces are set out in exactly the same way. Mark with a cross any pieces to be cut out. Next, with a fine saw held perfectly upright, cut down on the lines until the half thickness is reached, treating both pieces in the same way. On your discretion in cutting these lines will depend whether the joint is a good fit {see page 14). If you were now to take a chisel and a mallet, place the edge of the chisel on the horizontal line connecting the bot- toms of the cuts, and then give a good blow with the mallet, prob- ably two things would happen. A notch with an uneven slanting bottom would be formed, and the farther side of the work would be badly splintered. So first study the grain, and if you can see that such a course would be safe, you can take a good thick chip to start with, and then, using the chisel carefully — if the notch is a wide one adopt the sideways movement of the chisel — pare down, as in Fig. 89, until you have formed a flat surface flush with the line scribed on the side. Treat both pieces in the same way, test the bottom of the halvings for flatness and squareness, 31 Fig. 39. — Horizontal Paring in making a Halved Joint Every Boy His Own Mechanic fit the joint together, and make any adjustment required. In deepening the notch by a slight shave, if this should be necessary, the chisel is afterwards used as a knife to detach any parings that may still be held by their edges {see Fig. 40) ; it is drawn along in the angle of the cut with its front point raised, the flat of the chisel being in contact with the wall of the notch. Fig. 40. — Cleaning out the Halving with Corner of Chisel Fig. 41.— Starting Chisel on the Slant in Overhand Paring Overhand Paring. — For paring a short length off the end of a piece of work, start the chisel on the slant, as in Fig. 41, and when you feel that it is making progress bring it to the upright. Cut only a little at a time, and the work will be easier and of cleaner finish ; this applies to all chiselling. It will be obvious that in vertical paring, known as overhand paring, a great deal more power can be applied to the chisel. The work should be so held 32 USING SCREWDRIVERS 1 A Ibk ^«l^ ^5!" 1 \ - y ? 5 1 wm^ M|piM Hi.9 IL ■SS US j^%."jUilllff^ !• ] Narrow Screwdriver Injures the Screw-head Slanting the Tool Injures Screw- driver and Screw-head Removing Damaged Screw with Spanner Using Screwdriver-bit in Brace How to Use Woodworking Tools that the eye can look down the chisel and see that the paring is quite vertical. The left hand will hold the tool near the point and guide it to its work, while the right will grasp the handle, the^thumb coming on top {see Fig. 36). In later chapters I will show you how to make a few simple joints — the dovetail among them — and will illus- trate and describe a few wooden constructions upon which, if you can get the material, you may try your 'prentice hand. Screwdrivers. — The selection of a screwdriver is more important than some boys think. One of the plates in this book shows a narrow screwdriver used on a stout screw, the effect being to spoil the edge of the screwdriver and injure the head of the screw. To the right of this in the plate is a screwdriver held at a slight angle, a common ault with careless people. Here, again, the head is easily damaged, and once broken it may be difficult to get the screw out again. One method is to square the head with the file and to withdraw it by means of a spanner, this operation being shown in the plate. The screwdriver point or end should be almost parallel in thickness, and a fairly good fit in the nick of the screw. A powerful form of screwdriver is a brace into which a screwdriver bit has been inserted, such a combination being shown in use in the plate already referred to. I often use this device for driving long thick screws, but I find it has a big dis- advantage ; it is difficult to maintain the pressure so as to prevent the bit slipping from the head of the screw. The arm or crank of the brace gives enormous power, so much so indeed, that if the head of the screw is weak, or D 33 Every Boy His Own Mechanic the point of the screwdriver bit is inclined to be hard and brittle, either or both may be broken. The effect of using a screwdriver wider than the screw is to mark the work should it be necessary to insert the screw flush with the surface. The ordinary wood screw, actually of steel but known as a wood screw to differentiate it from screws for metalwork, has a countersunk head, and in careful work it will be necessary to chamfer or countersink the screw hole to accommodate it. The countersinking can be done with gouge or chisel or by means of a nose-bit or special countersinking bit used in a brace. To remove rusted-in screws, put the screwdriver in place in the nick and give a smart knock with a hammer to break the rust joint ; or try the effect of expanding the screw by heating it with a red hot poker. I give some information on the use of nails and screws in a much later chapter. 34 MAKING AND USING VARIOUS CEMENTS Cementing a Rim on a Biscuit Barrel. — These in- structions will apply just as well to the fixing of a mount or rim to the reservoir of a lamp, a glass pepper-pot, glass inkstand, and many other things. First with a bradawl scrape away the old cement from the glass or china article and also from the mount or rim, but take care in the latter case that you don't bend the metal and spoil the fit. Put some boiling water in a cup and drop in some crystals of alum, adding more and more until the water refuses to dissolve any more of the substance. Such a solution as this, as you have probably learnt in your chemistry lessons, is known as " saturated." When it is fairly cool, put a couple of spoonfuls of perfectly fresh plaster- of-paris in a saucer, add some of the alum solution, and mix up rapidly to a rather wet consistency. Then, without waiting, put some of the cement on the vessel or in the mount, and press the two parts into close contact, taking the greatest care that the mount " sits '* square and level. In half an hour's time any surplus plaster can be scraped away, and the vessel can be used twenty-four hours later. Another way, equally good, is to use powdered alum alone. First see that the articles are free from dirt and grease. Powder the alum, place the rim upside down, 35 Every Boy His Own Mechanic fill it with the powder, and put it on a metal plate over a low gas flame or on the warm kitchen range, and you will note that in the course of a few minutes the alum will get pasty. When this occurs, press the glass or china article firmly into the rim, quickly invert, see that the rim is in its correct position, and put aside for half an hour in a cool place, when the article will be ready for use. Cementing Celluloid and Xylonite. — Boys and girls use lots of things nowadays that are made of celluloid (xylonite is only another name for it). Girls have combs and hair ornaments and brush-backs and ping-pong balls of this material, whilst boys have celluloid knife-handles, celluloid accumulator cases and celluloid films for hand cameras and cinematograph machines. By the way, I once had some beautiful hair-brushes which I thought had backs of fine ivory, but one day I touched them with turpentine, and immediately I became aware of a faint smell of camphor. They were celluloid I You will know now how to test yours. It is just as well to find out which articles are celluloid and which are not, because, as you are probably aware, this substance ignites with an almost explosive violence. When celluloid gets broken, it may generally be easily cemented. It dissolves very readily in a liquid known as amyl acetate, which you will know by its strong smell of those sweets sold under the name of " pear-drops." So all you have to do when you want some celluloid cement is to put a few scraps of a broken celluloid toy, etc., in I oz. of the amyl acetate, and after the celluloid has dis- solved apply the solution with a camel-hair brush, and bring the two parts together. An excellent solvent for 36 Making and Using Various Cements celluloid is a mixture of equal parts of acetone and the amyl acetate. "Non-flam" film (made of a celluloid substitute which does not readily ignite) will not dissolve in either of the above, but will be found to do so readily in chloroform, which when not in use must be kept in a tightly stoppered bottle, a point which applies to all c.eUuloid solvents and cements. But chloroform is danger- ous stuff in the hands of inexperienced people. Fig. 3. — Cinemato- graph Film joined together Fig. 1. — Torn Cine- matograph Film Fig. 2. — Film with Picture Space cut out Cinematograph films are made of celluloid, and if you are called upon to repair them (they easily get torn when in use. Fig. 1 showing an example at a and b) you will need to cut out a picture, but this will make no appreciable difference to the effect on the screen. Cut the film as in Fig. 2, making one cut at the dividing line b, but leaving a little strip a, below the dividing line cd. Place the piece containing strip a on the table, and, first wetting the strip with the tongue, carefully scrape away the photo- 37 Every Boy His Own Mechanic graphic emulsion or gelatine below the line c d, using a penknife. Then apply the cement already mentioned to the back of b, and bring the two together, taking par- ticular care that the joint is absolutely square and other- wise correct {see Fig. 3). Keep under pressure till dry. China and Glass Cements. — I suppose most of my readers are called on some time or other to repair a broken article of glass or china. There are scores of cements that may be used for this purpose, apart from those that can be bought ready made. Plaster-of-paris, mixed with a solution of alum, as already explained, will mend china, but not so strongly as to allow of the article being washed with hot water or used as a hot-water container. An excellent cement for either china or glass is sodium silicate which possibly is employed in your household under the name of " water-glass " for preserving eggs. It should be used exactly as it comes from the lever-lid tin in which it is bought, and should be applied thinly, but it is desirable to warm the article, and the water- glass is more easily applied if it is warmed too. The article requires to be held together by tying tightly with string or by some other means until the joint is hard. A first-rate cement for china, glass and stone is a mixture of water-glass, manganese, and zinc white all ground up together ; and a putty that answers well for glass can be made by mixing chalk with water-glass. It is even better than the usual oilshop putty in one respect — it only takes a few hours to dry. A good many boys turn their hand to the making of an aquarium, and the usual cement used for this purpose is a mixture of various oxides of lead. One of the easiest 38 Making and Using Various Cements to make consists of the best quality white-lead, bought already ground up in oil, mixed with equal parts of dry red-lead and dry litharge. But remember in using lead cements that they are poisonous ; they should not, there- fore, be worked up in or applied with the hands, and after they have been given a week or two in which to dry and harden, the aquarium should have many changes of water before introducing either pond weeds or fish. Perhaps the safest way is to give the cement a few days to dry, and then apply three coats of good varnish, allowing at least two days for each coat to dry before applying the next. In any case, a few small minnows should be tried in the water before introducing valuable fish. Cementing Solid Tyres to Rims. — In the old days before pneumatic tyres were known, the solid tyres with which the " ordinary " bicycle was fitted had to be cemented to the rim. Nowadays, it is only mailcart and perambulator tyres — and those not of the best quality — which are so fixed. Should a tyre of this kind — the non-wired kind — become loose, you will find it a fairly simple matter to re-cement it in place, but it is a job requiring some amount of care. The cement used is a mixture of gutta-percha and pitch, and can be bought at any hardware stores. It may be used just as though it is sealing-wax, and the empty rim smeared with it all round, heating the cement in a candle flame or by means of a red-hot poker. The cement having been applied, stretch the tyre into place, and spin the wheel on its axle. Have ready a spirit lamp, which, as you know, has a smokeless flame, and as the wheel spins approach the flame to the rim so as to melt the cement evenly all round. Keep the 39 Every Boy His Own Mechanic wheel rotating, as otherwise there is risk of spoiling any paint or enamel on the rim, which, in any case, will not be improved in appearance. You can make a very cheap but efficient spirit lamp from a ginger-beer bottle by pouring into it some methylated spirit and then stuffing in a wick made of loose cotton strands. In the chapter on Cycle Adjustments and Tyre Repairs I deal with the cementing of patches on pneumatic tyres. Using Portland Cement. — If you have occasion to use Portland cement, small quantities of which can be bought at oilshops, of builders' merchants, etc., mix it thoroughly with an equal measure of perfectly clean and fine sharp sand, add a little water, and at once continue the mixing until you see the mortar is of a nice even texture. This will make a very strong cement and a more durable one than if the sand were omitted. For cementing a brick into place, or for any odd repair about the yard or garden, you can mix two measures of sand with one of cement. I put in a splendid floor to a summerhouse once with a concrete made by mixing 1 part of cement with 4 or 5 parts of sandy gravel dug up from a pit made in my garden. Such a floor will last scores of years, whereas a wooden floor often decays in a few years' time. 40 ERECTING ELECTRIC LAMPS AND BELLS Batteries. — What a great convenience it is to have an electric light over your bed ! I shall show you in this chapter how you can instal a tiny electric lamp more than enough to see the time by ; you can make the battery, erect the wiring, and connect up the lamp yourself, and be independent of any main-supply system. I have said you can " make " the battery ; so you can, but it is generally cheaper to buy it already made. However, 1 expect you are one of those boys who glory in making everything for themselves, and so in another chapter I am giving you full instructions on how to make a battery suitable for running a pea-lamp for a few moments at a time, using it only occasionally over a period of several months. This type of battery {see pages 112 to 115) is known as a primary battery, and it produces an electric current by the chemical action of the substances with which it is charged. There is a much more convenient type of battery, known as a secondary or storage battery, otherwise an accumulator. It contains lead plates immersed in dilute sulphuric acid, and is charged with current from a dynamo, from a primary battery, from another accumulator, from the electric-light main, or from whatever source of electric current happens to be convenient. The primary battery 41 Every Boy His Own Mechanic once exhausted needs to be recharged with chemicals ; the accumulator, when run down, simply requires a new electric charge. The accumulator is more expensive than the primary battery, but can receive and yield a far greater amount of current, and is a more reliable appliance. Now for a bedroom or workshop light, one or other of these devices is necessary unless, of course, you can afford a little dynamo and to run it by means of an engine of some kind ; but, generally speaking, the cost and the attention needed by the engine make such an arrange- ment rather out of the question, and most boys fall back on the accumulator or the simple primary battery. In another chapter, I explain how a Leclanche cell or battery is made. A really big cell of this type, say one that will hold about two quarts, will keep a metallic- filament quarter-ampere lamp glowing brightly for several minutes, after which it needs several days to build up its reserve of strength once more. Very few primary cells can ring a bell or light a lamp for long together. But this same big cell might last a year without giving any trouble, if it were just used now and then — a few seconds at a time — for illuminating a watch-stand, the face of a clock or the reception-room of your sister's doUs'-house. Much better results can be had from an accumulator of much smaller dimensions. A 4-volt accumulator of what is known as 5-ampere hour capacity would light a number of tiny lamps giving a total of 2 candle-power for as long as ten hours, which means that, as in " miniature " or " model " lighting, the lamps are seldom " on " for more than very brief periods at a time, the accumulator 42 Erecting Electric Lamps and Bells would last a long, long time on one charge, which charge, by the way, would cost only a few pence. Some Electrical Terms. — Amperes and candle-powers are all very well as terms, but what do they mean ? asks the reader who is new to this sort of thing. Well, we speak of the volume of an electric current in " am- Fig. 1. — Miniature Metallic-filament Electric Lamps peres," just as we speak of so many " gallons " of water. The force that drives a volume of current through any substance is measured in " volts," and the resistance which anything offers to the passage of the current is measured in " ohms." You must always remember these three terms — volts, amperes, and ohms. You must try to imagine a piece of any substance striving to prevent by 43 Every Boy His Own Mechanic means of ohms of resistance the passage through it of amperes of current which are being pushed along by volts of pressure or electromotive force. The pushing power is often referred to as " E.M.F.," meaning electromotive force, or as " difference of potential," or simply as " pres- sure." Amperes multiplied by volts gives us another term — watts. If I tell you that with small metal-filament lamps you can get 1 candle-power of light from 1 watt of current you will understand that a 1 -candle-power lamp marked 0.25 ampere will require a pressure or voltage of 4, because a watt is simply the product of amperes and volts multiplied together. Quarter-ampere multiplied by 4 volts equals 1 watt, and 1 watt in the type of lamp we have in mind equals (about) 1 candle-power. Systems of Connections. — Perhaps you know that when glow lamps first became popular their filaments (very fine wires) were of carbon, but nowadays lamp filaments are made of one of the rare metals, chiefly tungsten, and they give a better light than the carbon lamps and use less current. Why does the lamp glow? Simply because its fila- ment offers such a high resistance to the passage of the current that it become intensely hot, and, as everybody knows, most substances when raised to very high tempera- tures emit light. The filaments cannot burn because the bulbs have been exhausted of air. If you obtain a catalogue from a dealer in the smaller electrical supplies you will find in it particulars of a great variety of miniature lamps of different shapes and powers, and you will have no difficulty in selecting them to suit the supply of current you happen to have, but before you can tell exactly which 44 Erecting Electric Lamps and^Bells lamps to order, you must know how you propose to arrange them, and must understand the two or three methods of connecting up both batteries and lamps. There are two poles or terminals to both of these devices {see Fig. 1a). A battery has a positive pole at which the current is supposed to return. Inside the battery, current is supposed to pass from the negative pole to the positive. Thus the very first lesson to be learnt is that you must provide a circular path for the passage of a current. Not Neaafive Pole tkoafive Plate or E lee trod A flcldulated Water fhsitire Plate •or Electrode Fig. 1a. — Experimental form of Electric Cell or Battery only must you take the current out, but you must bring it back again. We will take a little cell and a two-yard length of copper wire. We will attach one end of the wire to one pole, and the remaining end to the other pole. In this way we have provided the circular path (as in Fig. 2), and current will instantly flow ; indeed, it will flow so easily that the battery will rapidly run down. The more resistance we offer to the passage of the current the longer will the battery remain in condition. 45 Every Boy His Own Mechanic We will cut the wire in the middle. There are now in effect two wires, one from each pole, and no current can flow. Taking a miniature lamp or even an electric bell, Fig. 2. — Cell and Simplest Circuit we connect the outer ends of the wires to the terminals (Fig. 3). Once again the circular path is provided ; we have " completed the circuit," and the current will at once do its work by causing the lamp to glow or the bell to ring. Fig. 3. — Cell, .Electric Bell, and Simplest Circuit We have now an electric circuit of the simplest possible kind. We can cut again where we like, and introduce a simple switch or push, by means of which we can " make " Fig. 4. — Cell, Bell and Push, and Simplest Circuit or " break " the circuit and glow the lamp or ring the bell whenever we like (see Fig. 4). Lamps or batteries so arranged that the whole of 46 Erecting Electric Lamps and Bells A S 4 A A n Fig. 5 Figs. 5 and 6 — Examples of Lamps and Cells con- nected in Series (A, ac- cumulator ; F, fuse or safety device; S, switch) HHH Fi«. 6 the current passes through each and all of them are said to be connected in " series " {see Figs. 5 and 6). Essentially the entire circuit is one endless path with the bells or lamps or batteries distributed to suit convenience. In a battery of cells connected in series the total voltage equals that^of all the individual cells added to- Q jy Fig. 7 T T T T Fig. 8 Fi^s. 7 and 8. — Examples of Lamps and CelU connected in Parallel 47 Every Boy His Own Mechanic gether, but the current in amperes is no greater than that of one cell. For example, two 2-volt cells each giving 1 ampere of current give, when connected in series, a current of 1 ampere at a pressure of 4 volts. In what is known as the " parallel " system, the current consists of the two main wires with the bells, batteries, etc., disposed between them — bridge fashion — with one Figs. 9 and 10. — Examples of Lamps and Cells connected in Series- Parallel - 1 1 li:)i'. - r i -r 1 Fig. 10 pole of each connected to one main and the remaining pole to the other. Such a system is clearly shown in Figs. 7 and 8. Cells connected in parallel to form a battery have a total voltage equal to that of one cell only, but the yield in amperes is multiplied by the number of cells. Thus the two cells already mentioned would give in parallel a current of 2 amperes at a pressure of 2 volts. Often a circuit has batteries connected in series and lamps or bells in parallel. This is known as series-parallel 48 WIRING ELECTRIC LAMPS AND SWITCHES Tightening the Pinch Screws Gutting off Ends of Wire Strands with Scissors Fixing Cord Grip of Lamp Holder Wiring-up a Wall Switch Erecting Electric Lamps and Bells (see Fig. 9). In Fig. lOj there are four cells disposed in tAvo sets. The two cells in each set are in series with one another, and the two batteries so formed are in parallel with one another. If each individual cell is 2-volt, 1-ampere, the current yielded by the whole battery will be 2 amperes at 4- volts pressure. Erecting Lamps and Bells.— With this theoretical information we may pass on to the practical work of in- stalling one or more lamps or bells. You will have de- cided on the type of battery you are going to use. Unless it is an accumulator or a home-made device, you will probably prefer a dry cell or cells, because they are non-spillable. Differ rermmal to be ■ connecred h push and-*', rhe of her one to ba fiery ■ Fig. 11. — Diagram showing Principle and Connections of Electric Trembling Bell clean, and give the minimum of trouble. You will choose a nice dry situation- but not a hot one. The contents of this type of cell are really moist, not dry, and if you put it in too warm a place such as over a stove, or near a chimney breast, it might soon fail, as a result of evapora- E 49 Every Boy His Own Mechanic Dther termmal to be -connecred To push and ■ the other one to battery tion. It is better to get a box that will take it just com- fortably and protect it from the atmosphere, and from your brother's prying fingers. If it is for a bedroom light, perhaps the box can go on a shelf, and be hidden by some books, or possibly room can be found for it in a cupboard, but not a damp one ; it gener- ally happens that small holes will have to be bored in the woodwork to allow the wires to pass. As only a few yards of the conduct- ing wire will be wanted — the shorter the run of wire the better — your best plan will be to buy the best insulated electric-bell wire (Stan- dard Wire Gauge, No. 16), and connect a length with one pole or terminal of the battery. To allow of slight adjustment of position, and to prevent vibration causing the wire to be disconnected, it is usual to form the last few inches of the conductor into a spring by winding it round a lead pencil, and then removing the pencil. 50 Fig. 11a. — Diagram showing Principle and Connections of Electric Single-stroke Bell Erecting Electric Lamps and Bells Doubtless you have seen it hundreds of times when ex- amining electric bells. You have now to decide the positions of the lamp and push or switch. In many of these arrangements I am now going to describe you can use either a bell or a lamp, providing that the battery is sufficiently powerful. You can easily prove by simple experiment that a little flash-lamp battery will ring an ordinary electric-bell quite vigorously, but not for long. A quart-size Leclanch^ cell will ring a bell or light a miniature lamp for a second or so at a time at fairly long intervals over a period ^^^^^^ of a year or more. "N ^^^g^ ^^ How an Electric Bell Works. — Per- '^^^^^^ haps I had better make it plain how a ^^m ^^ bell works. It consists, as in Fig. 11, ^^P\^^ of an electro-magnet d, a contact maker ^^^^^^^ and breaker e k J, an armature and ^'^^^^^^ hammer g h, and a gong n. The electro- f^^; sp^rlTgs tf Jsin magnet is two cores of soft iron wound ^"^^ with fine wire. Its poles F attract the armature and hammer only when current is passing through the coils. Immediately the armature is attracted and the gong in consequence struck by the hammer, the circuit is broken, current no longer flows through the coils, and the armature is released, only to re-establish the circuit again, ring the bell, again " unmake " the circuit, and so on. You can follow the passage of the current from terminal a, through spring c to coils d, then to the insulated contact pillar e, platinum contacts k, spring J, and thence by means of the metal frame l (indicated by the stipple lines) and through wire m to the terminal b. The above is an 5« Fig. 13. — Vertical sec- tion through Bell Push Every Boy His Own Mechanic ordinary " trembling " bell, a type that does not work well when connected in series with a similar bell. For series working, one trembling bell and the rest single- stroke bells (Fig. 11a) should be used ; in the latter, there is no " make-and-break " effect. A Simple Circuit. — You wish to light one lamp or ring one bell at pleasure from a push. This is the simplest of all electrical arrange- ments, and has already been shown in Fig. 4. Put the lamp or bell in the required position. From one terminal run a wire a to the battery. (In electrical diagrams the usual symbol for a battery is nil). From the battery's other terminal run a wire c to the push, continuing with wire b from the second terminal of the push to the remaining terminal of the lamp or bell. Fig. 4 shows a bell, but the diagram is equally correct for a lamp. The push is simply a little device for momentarily " making " or " completing " the circuit. It contains two springs, usual patterns of which are shown in Fig. 12, and the wires are connected individually to them. Normally these springs do not touch one another {see the section, Fig. 13), but they are made to do so when the little bone or ivory knob is pressed in, thus completing the circuit. A push is better on a miniature lamp system or for bell work than a switch (Fig. 14), because with the latter you may be tempted to leave the lamp or bell at work for too long 52 Fig. 14.— Simple home-made One- way Switch Erecting Electric Lamps and Bells Fig. 22. — Making Joint in Electrical Wires Suppose that the gas-pipe connection is out of the question, and that the electric bell is in your workshop at the foot of a long garden and the push is in your house, the bell being used to summon you to meals. You can still dispense with a second wire. At each end of the system bury at about 4 ft. or so some old waste piece of metal — an old clean oil-can or a leaky galvanised iron bath — and make good electrical connection with bell at one end of the circuit and push at the other. Pack round it some coke or gasworks breeze, and there you are ! But you need a rather damp soil to give good conductivity. Joints in Elec- trical Wires. — You will need to know how to join two electrical wires together. For purely tem- porary purposes simple twisting together is good enough. For permanent work, bad joints must never be allowed, since they oppose resistance to the current and waste it. Moist air soon corrodes exposed joints. First scrape off the covering, clean the ends of the wires with emery cloth, cross them and wind one round the other as in Fig. 22. Smear with " Fluxite," and use stick solder or coat with " Tinol " instead, applying heat with a bit or a Bunsen or blowpipe flame. In the case of branch joints (T joints), the connection is as shown in Fig. 23. 57. Fig. 23. — Making a Branch Joint Every Boy His Own Mechanic In all cases after soldering, replace any of the old insula- tion if this is possible, or, instead, wind on prepared rubber tape smeared with rubber solution, finishing with paraffined cotton. All these insulating materials are obtainable from the electrical dealers. If the Bell Fails. — Faults in electric bell systems often necessitate the use of a galvanometer for their detection, an instrument which not every boy mechanic is likely to have, but in simple systems of the kind which I have described in this chapter, providing that the wiring is erected carefully and in a common-sense way, there should be an entire absence of line faults, and what troubles may occur will be due rather to exhausted batteries, defective bells, and loose or dirty connections. If the bell rings sometimes and will not ring at others, you may sus- pect a loose connection somewhere in the system, and you may look for it especially at pushes, switches, and the bell. The scraping of contacts — especially the " platinum' ' contacts in the bell — with a knife or rubbing with a piece of emery cloth often works wonders on old bells and other fittings that have been in damp places. Many fittings contain a lot of brass, and brass is very susceptible to damp. Corroded brass always gives trouble electrically. If much trouble from damp is to be feared, take time in the first place to make really good contacts between the wires and fittings, and then touch the connections with vaseline, which will defy the damp for a long time. The use of flexible cord or cable is a great convenience, both for bell and model light work, but the tiny wires of which the cables are composed cause trouble if one or two are left loose ; thus one tiny wire projecting from a con- 58 Erecting Electric Lamps and Bells nection may easily cause a most baffling occasional ringing, and will exhaust the battery. In the course of time the battery will need renewal. If a wet Leclanche is in use the re-amalgamation of the zinc and the renewing of the sal-ammoniac solution will often work wonders, but in the case of a very old battery it may be necessary to renew the porous pot as well. But do not rush to the conclusion that the battery is at fault until you have examined the system in its every detail. Wiring up a Lampholder. — The lampholder to receive miniature lamps may have a cord-grip or a flange as shown respectively in Figs. 24 and 25. Flanges are for use on battens, etc., and the wires need to be conducted, to the terminals, behind the flange which is screwed to its support. The cord-grip holder is more generally convenient, as it may be suspended with a minimum of trouble exactly where it is wanted. It has a cord-grip D (Fig.24) which takes the weight of the holder and lamp off the actual terminals, thus preventing a fall of the lamp through the failure of the connections. The milled ring c holds the brass body to the porcelain interior, and the milled cap b supports a shade, whilst a is the cyhndrical part or socket in which is the well-known bayonet slot to receive the lamp. Inside the brass body above ring c is the porcelain fitting with terminals to receive the two ends of the circuit 59 Fig. 24.— Cord- grip Electric Lampholder Fig. 25.— Flanged Electric Lamp- holder Every Boy His Own Mechanic wires, the last-mentioned being bared of their insulation only just sufficiently to allow of their being clamped or pinched tightly into place. The terminals have little plunger contacts at the bottom which make flexible con- tact with the actual lamp terminals or with crescent- shaped brass plates in the lamp socket. Now in wiring up such a lampholder, the parts are, threaded in the following order : First the cord-grip, then the brass body, and then the porcelain interior ; the milled rings and socket containing the bayonet slot can be put on afterwards. The bare wires pass through holes in the porcelain body, and are held by the screws in the terminal blocks. Be careful when you are using flexible cable, which, as I have explained, consists of a large number of very fine wires, that no odd wires stray across to the opposite terminal, or even touch the metal sides of the lampholder, and so cause a short circuit. The bare wires having been connected, all surplus must be cut off close to avoid risk of short-circuiting. Then bring together the brass lampholder and the porcelain fitting, and screw on the milled ring which holds them together. The cord-grip contains two wooden fittings which are now to be put in place, taking care that they fit into the little groove which prevents their being twisted when the cord-grip is screwed down. The grip wedges the fitting to the support wires, and, as already stated, relieves the actual electrical connection of any strain. To put on the lamp shade it is generally necessary to invert the holder. Then the shade can be carefully in- serted over the screw threads, and the second milled ring 60 Erecting Electric Lamps and Bells or cap screwed on to hold it in place, but do not screw it up very tightly, or you may crack the glass shade. Attaching Wires to Walls, etc. — You may need a word or two with regard to the method of running the wire for a permanent job, but you will not forget my advice to get the best wire you can afford. Primary batteries easily run down if there is a small leakage anywhere, and leakage easily occurs when insulation is defective. Therefore, when putting up wire for a model lighting or an electric bell system in your den or workshop, and particularly if the wire has to cross places which are sub- jected to dampness, you would do well always to use wire having at least a rubber and double-cotton covering. A single-cotton insulated wire is all very well for temporary use in a dry situation, but not for much else. If you are putting up a system which is expected to last for years and the wires cross an open garden, you ought to use nothing inferior to a double-rubber or even a vulcanised rubber insulation. For a little system installed in your bedroom or den which will not be subjected to dampness, quite a cheap form of insulation will be good enough. But use nothing smaller than No. 16 gauge wire, remem- bering that the smaller the cross-section of the wire, the greater is the resistance opposed to the passage of electric current, and the less useful effect will you get. The circuit from battery to lamp or bell should be as short and direct as possible, for every extra foot of wire intro- duced means extra resistance for the current to overcome before it can start to do any useful work for you. If the wire has a proper insulation no more elaborate method of running it need be adopted than that of simply 6i Every Boy His Own Mechanic securing it to the woodwork by means of staples, but do not drive them too far home, as the very first thing to be remembered is that the insulation that covers the wire must on no account be damaged. For instance, if the two wires carrying current to and from a lamp or bell be placed under one staple, and you drive this home in such a way as to injure the insulation, the staple will form part of the circuit, which will now be " shorted." The lamp or bell might get a little current, but not much, and in the event of the push or switch being between the staple and the lamp, etc., your battery will rapidly exhaust itself. Ordinary wire staples can be used with care, and you can introduce a tiny scrap of old inner tube or any similar insulating material just under the head so as to minimise the risk of actual metallic contact between staple and conductor. Or you can obtain from the dealers special insulating staples, just as you please, or, better still, you can use a twin flexible cable and run it through insulated screw-eyes. This " twin-flex " is two cables twisted together, each consisting of a number of fine wires. The professional electrician runs wires through walls, floors and ceilings, but that is a proceeding which I do not advise the boy mechanic to attempt unless he has full permission to do the work, and also is perfectly sure before he starts as to what he proposes to do, how he will do it, and that in the course of the job he will not cause much unnecessary injury to the building. My firm advice is not to cut holes anywhere unless it be in a garden shed or workroom of rough construction where a few holes will do no particular harm. Wires are never drawn 62 Erecting Electric Lamps and Bells through the rough holes cut in brickwork, but for all such positions should be encased in metal piping. Holes are frequently cut in wood partitions by means of long gimlets (electricians' or wiremen's gimlets), and if care is taken to see that the holes are perfectly smooth, and that the wire is well insulated and not drawn too tight, I see no reason why for bell work or model lighting you should not dis- pense with tubes in such places. Generally avoid cutting and drilling, and run your wires wherever possible in such inconspicuous positions as the tops of cornices, picture rails, and skirtings, under window sills, etc. Sometimes you can run your wires up pipes to which you can secure them with little clips in the form shown in Fig. 21, or, as already described in this chapter, you might make the pipes themselves part of the circuit and simply connect the wires to them, using the same clip, and seeing that both pipe and wire are perfectly clean and bright so as to get good electrical contact. You can even dispense with clips by binding the circuit wire to the pipe by means of three or four turns of fine wire, everything being bright and clean as before. It saves much time and trouble to employ the twin flexible cable already mentioned, insulated with rubber and cotton, or, better still, rubber and silk, and simply to run it through insulated screw-eyes which are obtainable from all electrical dealers. A great advantage of using these special eyes, either closed or open, is that the wire is kept clear of the surface, and is therefore far less affected by any dampness which may be present in the walls or ceiling. The screw-eyes can be inserted at suitable places, and nothing is better and likely to do less damage than 63 Every Boy His Own Mechanic this method. The only difficulty may be in the case of ceilings, as unless the screw enters the lath behind the plaster, no fitting depending on it will be safe. Unless a slight discoloration shows the difference between the laths and the spaces between them, there is only one way of determining their position, and that is to probe in one or two places with a very fine sharp awl. When the screw-eyes are used, the flexible cable will need to be drawn very carefully through them, unless you go to the expense of using the sort with open eyes. These are very convenient, as all that is necessary is to lay the flexible in them and give the porcelain part a turn so as to close the eye. 64 THE HEKTOGRAPH COPIER: HOW TO MAKE AND USE IT I WELL remember when I was a small boy making a jelli- graph of my own invention, and thereby earning the sum of one halfpenny as profit, the writing out of a sheet of instructions on using the copier being thrown in gratis. Did I but know it, I ran the risk of an action for infringe- ment of patent rights, because at that time the hektograph, as the jelly copier is called, was the subject of a patent which did not expire until 1894. The jelligraph I invented consisted simply of one pennyworth of glue with, I think, a little moist sugar added, and it worked quite well until it dried up or went mouldy. It so happens that glue is the foundation of the proper hektograph jelly. It ought to be the best and clearest glue you can buy, and will be in the form of hard cake, not cloudy, nor should it have a decidedly unpleasant smell. If you can get the use of a flat metal tray holding about half a pint of water, you will need not more than 2 oz. of the hard glue, and as such a small quantity is required you can just as well afford the best as the worst. Wrap it in a piece of canvas, break it up with a hammer, place the fragments in a basin, and just about cover them with water. After a few hours you will find that the glue has swollen up into a jelly. Place this in an old clean handkerchief, or in a F 65 Every Boy His Own Mechanic piece of muslin, and squeeze off any surplus water. Borrow a 2-lb. earthenware jam-jar, and in it place the glue jelly, covering it with 10 oz. of glycerine. Put the jar in a saucepan containing a small amount of water, and bring the whole to the boil, afterwards allowing it to simmer, and stirring it from time to time to be quite sure that the glycerine and glue have combined to make a nice syrupy solution. The object of adding the glycerine is simply to prevent the glue drying to a hard cake and to allow of its being melted up time after time without losing its I moisture. Another ad- L 15 Fig. 1.- -Pattern for Metal Tray to hold Hektograph dition has now to be made, this time for the purpose of preventing the composition going mouldy. If you have ever discovered a piece of cake glue in a damp cupboard, you will know the state glue quickly gets into if not kept in a dry and airy place. A few drops of any essential oil — say, about ten drops of oil of cloves — will be all that is necessary. You can often detect the smell of oil of cloves in office pastes and similar compositions. Stir the oil into the composition, and straightway pour the contents of the jar into the tray prepared for it, placing the tray on a perfectly level table in a cool place until the jelly is set. I made the lid of a biscuit tin serve my purpose, but something a trifle deeper would be better. It is not difficult to make a tray at home from thin tinplate cut out to the pattern shown in the 66 The Hektograph Copier diagram (Fig. 1), and bent up on the inside lines, the little extra pieces or lugs to be bent round the corners where they will be secured with solder. Instructions on soldering are given in another chapter. The bending of the metal can be done over the perfectly square edge of a piece of board. I have often seen in ironmongers' shopfy trays costing only a few pence that would serve the purpose splendidly. I suppose you know how to use a hektograph ? Per- haps your school magazine may have been " printed " on such a device. The original must be written with a certain kind of ink, which is best bought ready made, but which, if you wish to do everything yourself, you can prepare at home by mixing together 2 oz. of methylated spirit, 2 oz. of water, and 4 oz. of glycerine, and adding about I oz. of aniline dye. Aniline violet will do for the blue- violet colour so common, aniline black for black ; methyl green for green ; eosin for red, etc. etc. The quantities given will make a good-sized cupful, which is probably ever so much more than you will need, but I don't think you can generally buy a smaller amount of the aniline colour I have mentioned. I am told that Judson's violet dye and Stephens' ebony stain answer very well as hektograph inks ; but personally I have never given them a trial. You will find no difficulty in using the hektograph. Gently stroke its surface with a soft, clean sponge, take off any surplus moisture with a piece of fluffless blotting paper or with a clean handkerchief, and then place the written matter face downward on the jelly and gently rub it into close contact with a handkerchief made into a 67 Every Boy His Own Mechanic pad. Leave it for about three minutes, and then peel it off by first raising it at one corner. To take a copy, simply place a piece of paper in contact with the jelly, gently press it into contact with the handkerchief pad, leave for a moment or so, and peel off as before. The later copies will require a much longer contact than the early ones. It helps to preserve the margin of the jelly surround- ing the transferred writing a (Fig. 2) from scratches, etc., if you lay down on the moist surface four paper strips ' B. A corner piece c just clearing the written matter makes it easier to raise the "printed" sheets. The number of good copies obtain- able will depend upon the quality and quantity of the ink (by the way, never blot the ink when writing the original, but allow it to dry naturally), and the care with which the hekto- protecting surface graph lias been used, but it ought not of Hektograph ^^ ^^ j^^g ^^1^11 about twenty, and is not likely to be more than twice or thrice that number. When the jelly is finished with, gently re-melt it in its tray over a small peep of gas or in a slow oven, and remove to a level surface to cool as before. In course of time the jelly will become coloured with the ink absorbed, and its appearance will be improved by mixing in a small amount of very fine whiting. A Putty Hektograph. — Some people think that the " putty " hektograph is far superior to the jelly. It certainly is more convenient in use, inasmuch as should any accident occur to spoil the smoothness of its surface, 68 8 B y. A B C . .^.^i: ' The Hektograph Copier which in the case of the jelly would necessitate re-melting, all that you need to do is to smooth it down again with a flat piece of wood. Then, too, after the number of copies has been taken, and you need to transfer or lay down another original, all you do is to wipe the putty with a wet sponge, blot up the surplus moisture with some fluffless blotting-paper pressed into close contact, and the hekto- graph is immediately ready for use again. It is a trifle more troublesome to make. Get 1 lb. of the finest whiting. You had better go to an artists' colourman and ask for "gilder's whiting." First of all only half the quantity is used. It must be in the form of a fine powder, and should be thoroughly mixed with, and beaten up with, 8 oz. of glycerine. Then leave it till the next day, by which time some of the glycerine will have come to the surface. The rest of the whiting, also in powder, should now be added. It will not be easy to incorporate the whole thoroughly well, but if you work at it in stages and put it aside for a few hours, you will find that in due course the glycerine will permeate the whiting. Finally, the mass will re- semble dough, which will need to be placed in a tray and rolled out perfectly smooth and flat with a ruler which will run on the edges of the tray. The method of taking the copies is the same as before. Let me revert to the jelly copier and give a word of advice. Materials vary, and the proportions given may occasionally need to be altered. If the jelly appears to be too soft, put it back into the jar and add a little glue, or, instead, keep it at the simmer for some little while. On the other hand, if the jelly gets too hard, re-heat and add glycerine, gently simmering for a time as before. 69 INSERTING A WINDOW PANE How often used I to watch a glazier at work and think how easy the job was ! I have not altered my opinion very much, but I know now that there were some things about the job I did not know then. Amateurs and especially boy mechanics, are so anxious to get the new . .^ glass in position that © © © ■''Ijini, '']. W\ they do not take V J llii|||ii|^^ i[ij, i|| iiA •' A L___l__i sufficient care to see Fig. 1.— Hack Knife that every particle of the old glass and especially of the putty that held it is first removed. That, after allj is one of the secrets of successful glazing. Let me assume (I am drawing on my personal history) that a cricket ball that never should have been " played about " with so close to the kitchen window has made a mess of one of the panes, and that you have offered to repair the damage done ! To remove the old putty, you will need a hack knife, and generally there is no need to buy the special tool shown in Fig. 1. Most houses possess a table knife that has been broken off short, and that will be the very tool for your purpose. With that and a hammer, you can cut out every morsel of the old putty. But be very care- ful that you do not chip into the woodwork of the frame. 70 Inserting a Window Pane You ma3^ come across a few brads, or tiny triangular pieces of sheet metal which have been driven in flush with the surface of the glass to assist the putty in holding the pane in place. Remove them with pincers. Thoroughly clean out the rebate or open groove until you are down to the bare wood. If there is an undercut groove in the top bar, take care to pick out all the old putty from it. If the hack knife is not of much use there, try a thin chisel, a bradawl, or a small screwdriver, but see that the putty does come out. Next carefully measure the rebate size of the frame. I may just remark that every frame that takes a piece of glass {see Fig. 2) has three sizes — the over-all size ; the sight size, that is, the measurement of that portion of the frame or glass through which the light passes, and thirdly, the rebate size, that is, the measurement across the frame, including the rebates or open grooves in which the glass lies. For example, a picture frame in front of me as I write measures 16 in. by 19 in. over-all ; the sight size — that portion of the glass which one can see from the front — measures 10| in. by 13| in. ; the rebate size is 11 in. by 14 in., which means that the glass is resting in a rebate about \ in. wide which has been made on the back inside edge of all four pieces of the frame. 71 Fig. 2.- -Diagram indicating the Three Sizes of a Frame to hold Glass Every Boy His Own Mechanic NoAv if this picture-frame were a window-frame, the piece of glass required to fit it would not measure 11 in. by 14 in., the actual rebate size. A glass of such dimen- sions probably would not go into the frame, but if it did it would be far too tight, and in very hot weather when the glass would expand, or as the result of any stress that might come upon the frame, the glass would easily crack. This, indeed, is the secret of those mysterious cracks which occur sometimes in picture-frame glasses when a room is unduly heated. So the piece of glass should be I in. smaller each way than the rebate size ; in other words, the glass will measure 10| in. by 13| in. Take the exact dimensions to the glass-cutter, tell him what the glass is to be used for, and he will give j^ou the right sort and exact size. Qualities of glass are known chiefly by the weight per square foot, the thinnest being " 15 oz.," and a usual quality being " 21 oz.," which is about y\, in. thick. For fairly large panes, " 26 oz." glass is used, this having a thickness of roughly | in. The first thing to do in inserting the glass is to prepare a bed for it by squeezing putty all round the rebate in one even thickness. This is generally done with the fingers, and there is nothing poisonous in glaziers' putty. Then the glass is pressed into position, rubbing it near the edges (not in the centre) with the fingers of both hands at once. Of course, use as much care as possible, especially if the glass is poor and thin. The pressure will cause the putty to squeeze out at the back {see Fig. 3), and you must continue the pressure until only a thin layer is left. If the pane is of fair size, and there is any risk of its being 72 Inserting a Window Pane blown out before the putty is hard, it will be as well to insert a few fine brads, driving them in sufficiently far that they will be covered by the facing putty when this is applied. These l>rads can be driven in with an old chisel. Sometimes professional glaziers use triangular pieces of zinc, quite tiny ■. 4), the Fig. 3. — Glass bedded in Putty Fig. 4.— Zinc Triangle Fig. 5. — Section showing Glass and Front and Back Putties scraps {see Fi instead of brads. The front putty is now put in {see Fig. 5), cutting it to a nice bevel with the putty knife (Fig. 6) which may be either a special tool bought for the ^H- 6.— Putty Knife purpose or a short stiff table knife. After this is done, but not before, use the same knife to cut away the surplus putty which has been squeezed through at the back. It is as well to leave the pane untouched for a week after completing the job. 73 VARIOUS WORKSHOP METALS: HOW TO IDENTIFY AND WORK THEM So many metals (iron, copper, aluminium, lead, zinc, etc.) and alloys (steel, gunmetal, brass, solder, etc.) are used in metalworking, that the boy mechanic may be at a loss to distinguish one from the other. Even experts find it difficult to tell some steel from some iron, and to distinguish between certain qualities and varieties of steel itself. Then again the alloys are legion, and only a skilled metallurgist and chemist could identify some of them from others. So I shall speak in this chapter only of those everyday metals and alloys which the reader is likely to handle in his home workshop. Cast Iron. — This is a very impure iron obtained by smelting iron ore. Pure iron does not exist in the engineering workshop or in commerce. Indeed, it is the impurities, sometimes, which give iron its special value. Cast iron is harder than mild steel, but softer than hard- ened steel, as to which I will give more information later. The weight of a metal or alloy will be some guide in identifying it, and in every case I will give the weight in ounces per cubic inch. Cast iron weighs slightly over 4 oz. per cubic inch. It is very brittle, so much so that dropped on a stone floor a cast iron article will generally break. It cannot be bent, but can generally be filed, 74 Various Workshop Metals chipped with a chisel, or sawn with a hack saw; but in using a chisel, always remember that the metal may be so weak that the whole of the casting may be broken by a heavy blow. In cutting cast iron with a file a powder is produced, whereas when wrought iron is worked, the filings take the form of very small shavings. This is because the cast metal is very brittle, and the wrought metal tough and fibrous. Touch a piece of cast iron with a drop of nitric acid, leave it on for a few minutes, wipe off, and thoroughly rinse with water ; you will see a dull black spot representing the carbon in the metal which has been laid bare by the dissolving away of some particles of the iron. Wrought Iron. — This is refined cast iron, most of the carbon and impurities having been removed by re- melting, and it is usual for the wrought iron to be rolled into plates, rails, bars, and rods. The weight of a cubic inch is about 4| oz., but varies slightly. What a different metal this is to the cast iron ! Its brittleness has vanished, and in its place is a toughness which renders it, next to steel the most reliable metal in the world. It is of a fibrous nature (cast iron and steel are not), it can be bent double without breaking, and it can be filed, sawn, drilled, and chipped quite well, although its tougher nature makes the work a little more arduous than is the case with cast iron. In working wrought iron, you can use a lubricant — either oil, or very soapy water. Tested with nitric acid in the way already explained, you will reveal a dull greyish spot, there being very little carbon in this metal to be brought into prominence by dissolving away of the iron particles. Wrought iron can be welded — that is to 75 Every Boy His Own Mechanic say, two pieces of it made red hot can be hammered to- gether to form one. Mild Steel. — There is more than one way of making mild steel, but the principle is to refine cast iron, add carbon and put the metal through a process which actually alloys the carbon with the iron. The steel is squeezed out between rolls to the shape required. A cubic inch of mild steel weighs about 4| oz. It is softer than most other irons and steels, and like wrought iron it can be easily bent cold, is weldable, and can be worked with file, saw, and drill, although with greater difficulty, as it is a tougher metal. Unless a file is rubbed with chalk or oil it soon becomes " pinned " with either wrought iron or mild steel ; that is, the spaces between the teeth get filled up with the detached particles of the metal. Cast Steel or Too! Steel. — This is commonly called crucible cast steel ; it is a " high carbon " steel, that is, it contains a fairly high percentage of carbon actually alloyed with the iron, and the result is to change the whole character of the metal, which becomes quite different from cast iron, wrought iron, or even mild steel. It now has a property which not one of the materials just mentioned possesses — it may be hardened by heat treat- ment : Made red hot, and suddenly plunged into oil or water, it becomes extremely hard and brittle. If it is too hard or too brittle for the purpose in view it needs to be heated to a temperature much below the first and then either allowed to cool of itself, or plunged into oil or water as before. This second treatment is known as tempering, inasmuch as it has "tempered" the extreme 76 Various Workshop Metals hardness. It is this ability to be rendered extremely hard at the will of the worker that makes carbon steel so useful. A tool made from it can be ground and sharpened to a cutting edge, and the steel will be hard enough to retain it, whereas a cast-iron tool would be broken the first time the tool were used, and one of wrought iron or mild steel would be turned up. Tool steel is manufactured by melting some such material as blister steel in a crucible and adding an ore rich in carbon. The blister steel mentioned is itself sometimes used for the making of inferior tools, and is the result of heating cast iron and charcoal to a high tempera- ture, the steel when cold showing blisters on its surface. Cast steel is obtainable by the worker in the form of rods and bars. It may be filed in its unhardened state, but it is wise to use an old file for the purpose. Frequently it is difficult to work tool steel unless it is first annealed, a process which consists in slowly but thoroughly heating the metal, and then burying it in cinders or ashes so that it cools very slowly, this having the effect of thoroughly softening the steel. The same lubricant as used for wrought iron and cast iron (oil or very soapy water) answers when filing, sawing, drilling, etc. As brittleness always accompanies hardness, it is possible to break off a piece from a steel bar or rod by first filing or chiselling a nick all round, and then giving a blow with the hammer. Very hard steel will scratch glass, so that you will quite understand it is out of the question to think of filing or sawing it, but until the hardness has been given it by the heat treatment already referred to, it can be worked with the ordinary cutting tools. A piece of tool steel tested 77 Every Boy His Own Mechanic with nitric acid, as already explained, will show a brownish black spot. Copper. — This metal is obtained by smelting certain ores and refining the product a number of times. One cubic inch weighs about 5 oz. It is softer than tin or zinc, and is very malleable, more so than iron or steel. Filing, sawing- drilling, etc., are affected by the clinging nature of the metal, but the work is all the easier for using a soapy water lubricant. There are many valuable alloys containing copper, the strongest being phosphor-bronze, a mixture of copper, tin, and phosphorus, capable of standing great wear, and for that reason used in machines for bearing surfaces, etc. Bronze or gunmetal is another very valuable alloy, con- taining from 85 to 90 per cent, of copper and 15 to 10 per cent, of tin ; this alloy is fairly easily worked, but as the percentages of the two ingredients vary so much, it is not easy to give definite particulars. A cubic inch weighs rouglily 5 oz. Brass is an alloy of 70 to 80 per cent, of copper, with 30 to 20 per cent, of zinc, an average brass weighing nearly 5 oz. per cubic inch, and being harder than silver. Cast brass is softer than tin, but the drawn brass is harder than that metal. Brass is very easily filed, chipped, sawn, drilled, etc., but needs to be treated cautiously owing to its lack of strength. Neither brass nor gunmetal requires a lubricant in working. It is ex- tremely important to work in a new file on brass, and afterwards use it on iron and steel. Tin. — This is a metal which is not often used alone. It is obtained by smelting certain ores, and its chief use is to alloy with lead to make solder, and to alloy with 78 Various Workshop Metals zinc and copper to make babbit metal, which, being harder than lead; but easily melted, can be readily moulded and cast, and is commonly used as a bearing metal. Tin itself is harder than lead, but softer than zinc, and a cubic inch of it weighs about 4| oz. You frequently see in a book some such instruction as " Take a sheet of tin and bend it," etc. etc. What is meant by an instruction of that sort is, take a piece of " tin plate," which nowadays is thin mild steel that has been coated with tin to protect it from attack by atmosphere and moisture. Tinning is a very easy process, as any metal which has been perfectly cleaned, and made hot, will take a coat of tin if brought into contact with that metal ; see, for example, what another chapter has to say with regard to the tinning of a soldering bit. Lead. — This is the softest of workshop metals, but a very valuable one. It is extremely malleable, and will go into almost any form when worked by a hammer. It is so soft that it can be cut with a knife, which will leave a bright metallic lustre. It is heavy, a cubic inch weighing slightly more than 6| oz. Few acids have any effect upon it, but either nitric acid or aqua regia (1 part of nitric acid mixed with 2 parts of hydrochloric acid) readily dissolves it. It is easily filed, but very rapidly gives trouble owing to the clogging up of the file, for which reason, a single-cut file {see p. 98) is preferable to the ordinary double-cut file, this also applying to solder, aluminium, and copper. Zinc. — This is another useful metal at times, but is chiefly used alloyed with copper to make brass. It is of about the same hardness as tin. It is a bluish white 79 Every Boy His Own Mechanic metal, and weighs about 4 oz. per cubic inch. Used in batteries it requires to be amalgamated with mercury {see p. 112). Aluminium. — This is made in the electric furnace and has proved to be one of the most useful metals ever discovered. It is the lightest workshop metal, a cubic inch weighing barely 1| oz. It can be bent and worked without difficulty, a good lubricant being ordinary paraffin oil or turpentine. A file is soon clogged by it. I mentioned just now the ease with which metals are tinned, but aluminium is the exception, and this accounts for the great difficulty in obtaining a really satisfactory soldered joint in this metal. Should you ever try to solder alu- minium, get one of the special solders containing phos- phorus, and use a bent copper bit by means of which you can well scrape the solid surface before and while melting the solder. Hot aluminium oxidises with extreme rapidity, and immediately a film of this oxide forms it must be scraped off and the soldering instantly proceeded with unless the flux or the solder used has the property of dissolving aluminium oxide. The phosphor solder has this property, and when combined with the use of a bent bit, gives undoubtedly the best results obtainable, short of welding by means of the oxy-acetylene blowpipe flame. Aluminium bronze is a useful alloy, this being made by melting together either copper or bronze with 5 to 10 per cent, of aluminium. Expensive and Precious Metals. — Silver, gold and platinum have valuable qualities from the metalworker's point of view, but their expense prevents their being generally used. Silver, however, is commonly employed 8o o < H Various Workshop Metals in soldering (see p. 135). It is harder than gold, but softer than brass or tin, and a cubic inch of it weighs about 6 oz. Gold is the only yellow metal, and resists the action of most commerical acids, although it is easily dissolved by aqua regia, the proportions of which have already been given. It is harder than lead, but softer than silver, and its weight is about 11'16 oz. per cubic inch. Platinum, which is one of the whitish metals, and is even harder than gold, also resists the action of acids, even aqua regia having only a slow action upon it. In hardness it is below most qualities of drawn brass. It is extremely heavy, a cubic inch of it weighing from 12 to 13 oz., according to the preparation and treatment the platinum has received. Its extremely high cost puts it beyond ordinary reach. 8i MAKING PICTURE FRAMES One of the most useful and pleasurable jobs falling to the lot of the boy mechanic is the framing of a picture. This is a simple matter if the frame is already made and sup- plied with glass cut to size, but I propose to show you in this chapter how to do the work from the beginning. Not that I shall go into the making of the moulding from which the sides of the frame are cut. Few people Fig. 1. — Sections of Picture-frame Mouldings make their own mouldings nowadays. The manufacture of composition mouldings is a trade to itself, and the more desirable mouldings in oak, rosewood, ebony, etc., are seldom made nowadays with shaped plane cutters, but instead are produced in length and with ease on a machine known as the vertical spindle. This is a rapidly revolving spindle to which is clamped a cutter block containing four shaped cutters. The spindle revolves at 82 Making Picture Frames a very high speed, and strips of wood are guided past the cutters, which instantly remove the chips and produce the moulding before your eyes. All sorts of mouldings are obtainable at picture-frame supply shops, but take my advice and for your early efforts use solid stuff, neither veneered nor faced with plastic composition. Fig. 1 illustrates in section a few of the many patterns of solid oak mouldings available. Flat gilt slips (Fig. 2) may be used with simple mouldings of the kinds shown. Equipment. — Your woodworking tools will be required Fig. 2. — Sections of Gilt Slips for Picture Frames Fig. 3. — Mitre Box in frame making, and, in addition, one or two special appliances for cutting and finishing the mitres at the frame corners. First these mitres are cut with a fine saw — tenon or dovetail — and are then faced up with a keen finely-set plane-iron, and for both of these jobs some special device for guiding the tools must be adopted. For sawing the mitres, either a mitre box or a mitre block is necessary — preferably the former. It is a trough (Fig. 3) across the top edges of which have been set out, with extreme accuracy, two intersecting angles, each of 45°, the lines being squared over on the sides as indicated. A saw is then run down in two directions so as to form 83 Every Boy His Own Mechanic slanting cuts, those on one side being, of course, in perfect alignment with those diagonally opposite. Any good odd stuff will do for the box, 1 in. being a suitable thick- ness. After the box has been in use for some time, the entrances to the saw cuts will become worn, to prevent which a set of four pairs of iron guides may be bought from a tool-dealer and screwed on. Very convenient forms of mitre boxes are sold, and, in general, the amateur is well advised not to make his first appliance of this kind. The mitre block (Fig. 4) is on the same principle as the box. and need not be particularly described ; it is an alternative to the other, but is not recommended in preference to it. Cutting the Moulding Lengths. — Before cutting up moulding, make a rough drawing of the frame Fig. 4.— Mitre Block o^" frames required (it generally saves time to make two or three frames together), and be absolutely certain as to your measurements. Remember that a frame has three dis- tinct sizes (as explained on p. 71) — the over-all, rebate and sight — and the picture and glass should be very slightly smaller each way than the rebate size of the frame. A little scheming will make for economy. A length of picture moulding is usually about 12 ft. To estimate the length of moulding required to frame a picture, add together the lengths of the four edges of the picture mount, add four times the width of the moulding, and allow a trifle for cutting. Thus, a 12 in. by 10 in. picture will require of 1| in. moulding : 84 Making Picture Frames 12 in. 12 in. 10 in. 10 in. 6 in. (1| by 4) Fig. 5. — Mitre Shooting-board 50 in. ; add to this 4 in., an ample allowance — total, 4 ft. 6 in. Thus a 12 ft. length of moulding would make two frames of the rebate size above mentioned, and have a surplus of 3 ft. or slightly more. It is Easy to Cut the Moulding in the Wrong Place. — Moulding is ex- pensive, and if cut thoughtlessly will often be wasted. For cutting, hold it in box or block, and run down the fine saw, using it lightly. Cut a long side first, from it scratch off the length of the opposite member, and pro- ceed to cut that. There will be trifling differences in the lengths, I expect, but you can correct these when " shooting " or finishing. Do the shorter sides last and cut the pairs of sides for all the frames in hand before proceeding further. "Shooting" the Mitres. — The sawn edges or faces are sufficiently rough and inaccurate to prevent all four joints being of neat appearance when viewed from the front. They have yet to be planed on a mitre shooting- board, which is a device for holding the moulding in such a position that a plane lying on its side and guided by 85 Fig. 5a. — One-piece Frame with Ornamental Head Fig. 5b. — Jointed Frame with Bar Fig. 5C. — Mitred Frame with Fretwork Ornament 86 Making Picture Frames contact with the board may be " shot " across the sawn face and caused to remove the saw marks. The mitre shooting-board may be bought or can easily be made by a careful amateur from f in. to 1 in. stuff, well planed and perfectly parallel, by screwing a narrow board to a wide one, as in Fig. 5, and then screwing on an equilateral triangular piece (known as the fence) also as shown. The edges of the triangle will make angles of exactly 45 deg. with the front edge of the narrow board. The plane is Fig. 6. -Mitre Shoot In use ; showing also how to set the Fence with help of Set-square used on its side, edge of cutter towards the triangle {see plan of a different pattern of shooting-board, Fig. 6), and will need to be in perfect condition, the cutter being very keen and projecting only slightly. For shooting joints, the cutter needs to be sharpened like a chisel, quite square or straight {see p. 21). A still simpler mitre shoot which anybody can make for himself is shown in Fig. 8. It is a wide piece of wood, A, with one edge planed straight, screwed down upon it at an angle of 45° with the edge being a wooden 87 Every Boy His Own Mechanic strip — the fence. The angle line can be set out with set- square or bevel-square. To use a mitre shooting- board, lay the moulding down face uppermost and with its outer side (not the rebate side) in close contact with the fence, the sawn end just projecting over so that the plane, worked by the right hand while the left holds the moulding, will Fig. 7.— Small One-piece Frame for merely clean off the rough- staading or hanging ness and nothing more. Do both of the ends, of course, then proceed with the other pieces, and again compare and check the lengths of opposite pieces, placing the rebated edges together for the purpose, and effect any correction necessary. You will see in the tool catalogues quite a number of special tools and appliances for frame mak- ing. I can only say of them that the profes- sional frame- maker leaves most of them alone, but there is one that is Fig 7a. — Another simple One-piece Frame 88 Making Picture Frames coming more and more into popularity, and that is the mitre trimmer, cheap patterns of which are now available for amateurs' use. The sawn moulding is put into the trimmer, a lever pulled, and a keen chisel-edge takes a light cut over the mitre and effects a great saving in time as compared with the use of plane and shooting-board. Gluing and Cramping. — The mitred members are now to be joined together with glue and nails, and I will explain just one Avay, and that the simplest, in which this may be done. Four corner blocks (Fig. 9) for each frame will be wanted. They can be cut with a turn or com- pass saw from thick wood, or, more easily, sawn off from a circular piece of stuff 2 in, or more in dia- meter. Cut out the square Wfl . Fig. 8. — Simple form notch to receive the frame I ,' of Mitre Shoot corner, and cut one or two ■■ * string grooves with a saw as shown, finally cleaning the whole up with glasspaper to remove any roughness that might abrade the string used in tightening the joints. Build up the frame on a sheet of newspaper covering a bench or table, and put a block a (Fig. 10) at each corner. Pass a length of strong smooth string b round the whole two or three times, and tie the ends securely. Get four short sticks c, insert them between the strings and twist several times so as to tighten the string and puU the joints close together, as in Fig. 10. If they go right home and the work needs no further correction, loosen the string, remove the mouldings, coat the joint surfaces with good 89 Every Boy His Own Mechanic hot glue, replace, and again tighten up, leaving all night for the glue to get hard. Apply the glue smartly, and have the mouldings fairly warm in readiness. If the frame is of any size., strengthen each joint next day by inserting a fine nail or screw from the side {see Figs. 11 and 12), or by gluing in one or two pieces of veneer, as in Fig. 13, first making a saw-kerf, as at A, inserting glued veneer, as at b, and cleaning off when dry and hard. Plenty of special frame cramps are obtainable at dealers', but the one here described costs almost nothing and is quite efficient. Fitting Up a Frame. — Next we will proceed to fit up a frame with glass, picture, backboard and screw-eyes. You will probably get the glass cut to size, ^2 ^^' l^ss each way than the rebate size of the frame. But if you cut it yourself with diamond or v/heel glass-cutter, see that it is Fig. 9. — Corner Block for Picture- frame Cramp Fig. 9A. — One-piece Frame with Oval Opening 90 Making Picture Frames bedded perfectly flat upon a freshly-dusted table top on which a newspaper has been spread, and use the instrument with steady uniform pressure ; otherwise you are almost certain to crack the glass. All that the diamond or wheel-cutter does is to scratch the surface, and the glass, being very brittle and weak, easily parts at the scratched Fig. 10. — Cramping Picture Frame with Corner Blocks and Twisted String line. A fine file can often be converted into a cutter for common qualities of glass. It must be " glass-hard," and can be made so by heating in a fire or blowpipe flame to bright redness, and immediately plunging into cold water. It will now easily break, leaving extremely sharp edges which can be used exactly as a diamond. They wear rapidly, but a new cutting point is easily made by breaking off a further piece. 91 Every Boy His Own Mechanic Fig. 11. — Nailed Frame Joint The cut glass should be well cleaned, and personally I have always used methylated spirit, which dries quickly and leaves a bright polish ; but you can do quite well without it. The backboard of a frame is thin, rough-sawn and often faulty stuff, which can be bought in lengths of about 6 ft. and in widths up to 12 in. It will need to be sawn or cut with a knife or chisel to size. The rebate in the frame should be deep enough to take glass, pic- ture and backboard, but it often proves to be too shallow, in which case the margin of the backboard must be bevelled, as shown in the section (Fig. 14), to permit of the headless tacks or sprigs being inserted. I find that the best means of diiving in the sprigs is an old chisel used flat, so that its side near the point acts as a hammer, and I place a flat iron on the bench or table against the frame so that its weight is added to tliat of the frame and makes the nailing easier. Smoke and dust have a wonderful way of working into a frame, and it is always wise to cover the whole of 92' Fig. 12. — Screwed Frame Joint Fig. 13.- Keyed Frame Joint Making Picture Frames the back with a sound piece of brown paper pasted on at its edges. To make assurance doubly sure, you can first of all paste on 2 in. strips of paper to hide the rebate and any joints in the backboard [see Fig. 15), afterwards covering all with one piece. Fig. 14. — Section of Fitted Picture Frame showing Bevelled Back Board secured with Sprigs C ,• Fig. 15. — Paper Strips pasted over Cracks to exclude Dust Screw-eyes or screw-rings need to be inserted to com- plete the job, first boring little holes for them, but making- certain that the screws do not come through to the front of the frame. Special cord for picture frames is sold, but I prefer wire, which is finer and neater. Brass wire 'soon corrodes, but gilt copper wire will last a long time. 93 HOW TO USE METALWORKING TOOLS Bench and Vice. — Most metalworking demands a heavy bench or table, but perhaps you can make do with a small rigidly-built table with a 2-in. thick plank laid on it to receive the roughest of the wear. A vice of some sort is a very great convenience. You can get along Fig. 1. — Heavy form of Bench Vice with Parallel Action Fig. 2. — Table Vice, fixed by Turnscrevv from underneath without one, but not easily. The heavier and stronger th vice the better it will be, but a small vice is better than nothing. I give in Fig. 1 a diagram of a good solid type, and you can look up prices and pictures of other sorts in almost any tool catalogue. A leg vice that, besides being attached to the bench, actually rests on the floor, is an advantage, particularly when the bench is too slight to stand much heavy work. Fig. 2 shows a type often favoured by amateurs. 94 How to Use Metalworking Tools Hack Saws. — Immediately we start to do any metal- work, however rough and simple, we notice the particular need of saw and files. A hack saw is a very hard steel saw with fine teeth, and it is used for cutting brass, copper and even iron and steel. The saw itself is a blade held in tension by a frame, one of the simplest kinds being shown in Fig. 3. In this, after the blade is inserted, the winged nut on the outer end has to be turned until the saw is Fig. 3. — Cheap Cast-Iron Hack Saw Frame Fig. 4. — Sleeve-adjusting Hack Saw Frame taut. A saw that I have found very convenient is a cheap pattern, the length of which is adjustable (see Fig. 4). The two clamps are first placed in position, the saw threaded over the two pins which the clamps carry, and the wing nut then given two or three turns as may be necessary to make the blade tight. A better kind is adjusted entirely from the handle. You will note directly you get a hack saw into your hands that the blade can be set for cutting either downwards or upwards, or even sideways, either to the left or right. It is well to remember this, as the ability to use the saw sideways is often an advantage. Get the best saw blades you can 95 K -^"A Hot Hand Knife o a A Round Sq. 3 comer Fig. 5. — Sections through various Files Every Boy His Own Mechanic afford, and remember that as the saw cuts on the forward stroke, the teeth should point away from the handle. Do not apply too much pressure when using it, and push it neither too fast nor too slow. On copper and the various copper alloys for which a saw with twelve teeth to the inch is roughly correct, the speed of working should be about a double stroke every second, whereas on iron and steel, for which the teeth must be very much finer (about twenty to the inch), little more than a single stroke a second would be enough, but it is not only the speed that counts, the right method of holding the saw is a great factor. First see that the work is supported at the right height for you. It should be very slightly lower than your elbow when you stand up. The handle of the saw is gripped in the right Fig. 6,— Various Files : A, Flat ; B, Bellied , , 1 •! J.1 Flat ; C, Square ; D, Triangular or Three- hand, while the cornered; E, Round; F, Half-round; G, left hand holds Knife-edge 96 How to Use Metalworking Tools the front of the saw frame and not only assists it to and fro, but holds it down to its work. Files. — These are of various kinds, and you can spend a lot of money on them if you want to, but don't. Make do with as few tools as possible. In Figs. 5 and 6 I show a few of the shapes with their names. Files are made in three grades, known respectively as bastard. Fig. 7. — Position for Filing second-cut, and smooth, and, as a rule, the second and third kinds, from 6 in. to 9 in. long, best suit the require- ments of the boy mechanic. A convenient shape is the flat tapering, the three-cornered or triangular file always comes in useful, and perhaps the next best choice is a half-round. By the way, in Swiss files six different cuts H 97 Every Boy His Own Mechanic can be obtained instead of the three in English ; and numbers three and four will be found generally useful. Some files are single-cut, and others double-cut, that is, in the second two series of teeth have been made in the file, other. The single - cut and alloys of a soft Fig. 9. — How File Is held for Heavy Work Fig. 10.— How File is held for Light Work one at an angle to the file is best for metals clinging nature, and the double - cut for iron, steel and the harder alloys, such as gunmetal, bronze and high quality brass . Fig. 7 shows you the proper position. It is so easy to get a rounded surface when filing, the work rising up in the Fig. 11.— How File is held for Draw-filing middle and fall- ing away at the edges. The right hand wants to drop, the left hand to rise, and you have to correct this tendency, and put in a lot of practice before you can get a flat surface by filing. Figs. 7, 9 and 10 show how to hold a file, whilst Figs. 8 and 11 show the positions of body and hands for di'aw-filing, the best method of dealing with long and narrow surfaces; the file should be chalked slightly and drawn over the work. 98 How to Use Metalworking Tools A test often given a mechanic when entering a new workshop for the first time is to file up a piece of steel flat and square. It is ever so much more difficult than you think. Scrapers. — I do not suppose that you will do much scraping of metals, but should you be a model engineer and attempt any serious work, you will have to know how to prepare two pieces of metal so that they will work Fig. 12.— Flat Scraper Fig. 13. — Triangular Scraper m Pig, 14.— Good and Bad Shape of Triangular and Flat Scrapers respectively over one another and yet be so close together as to resist the passage of steam under pressure. Just as filing smoothes a surface produced by the use of the saw, so the scraper makes still smoother a surface as it comes from the finest of files. There are countless shapes of scrapers, but a lot of useful work can be done with the flat- ended and triangular shapes (Figs. 12 and 13). The first has a slightly-rounded edge and can be bought ready for use or may be made from a worn-out file of the right 99 15. — How the Fiat Scraper is held WEOOE. Every Boy His Own Mechanic shape by first annealing it {see p. 77) and then on a wet grindstone grinding off the teeth, afterwards bringing up the edges on an oilstone. It must be made extremely hard by heating to bright redness and cooling in water. Scrapers are used with short forward strokes, not more than in., and the tool is grasped in the two hands. The angle at which the tools are used is shown in Fig. 14. Hammers. — I hardly suppose you will go to the ex- pense of a separate hammer for metalwork, but remember that "any old hammer" is sometimes a danger, both to you and the work. It may badly mark any metal on which it is used forcibly, and should it be used to propel a chisel or a punch, it might easily glance and bruise your hand. Three engineers' ham- mers are shown in Figs. 17 to 19. Do you know the right way of securing the head to the shaft or handle ? With a really sharp knife, lightly pare the wood to the correct shape until head and handle are a tight fit. Separate them, and make a saw-cut down the handle across the Saw- CUT HAMM&R, SHAFT Fig. 16. — Wedging Hammer Head on Shaft (Hammer shown is the Woodworker's "London" or "Exeter" Pattern) JOO How to Use Metalworking Tools greatest width (see Fig. 16). Drive the shaft into the head again, and have ready a wedge of hard wood, and drive this into the saw-cut. Some people use an iron wedge, which holds very well for a time, but ultimately rusts, and then the head is liable to fall off. Soaking a loose hammer head, with the shaft in position, in water tightens the head. Fig. 17.— Ball-paned Hammer Fig. 18. — Cross-paned Hammer Fig. 19.— Straight- paned Hammer Chisels. — Expert mechanics can do a great deal on iron and steel with a hammer and chisel, and you will find it worth while to emulate them to some extent. A small casting, for example, that you may be working up will probably need grooves and recesses cut in it which would mean a lot of troublesome work with a file. There are flat chisels (Fig. 20), straight-edge chisels, wide and narrow, cross-cut chisels, and diamond-point chisels (Fig, 21), and for cutting grooves the last-named will be useful. The chisel edge will not have the keenness of a wood chisel — 30° for brass and copper, 45° to 50° lOI Every Boy His Own Mechanic for most iron and mild steel, and 65° for hard steel. You remember that a plane-iron is slightly rounded at the corners to prevent its digging into the wood. Well, a metalworker's chisel of any width is treated in just the same way {see A, Fig. 20). With such a chisel less metal is cut at a time certainly, but the work is easier. Drills. — For making holes in metal there are two distinct methods. Iron and steel can be made red hot and holes then punched in. That is the blacksmith's n /C=^ (n is all you need to know about the materials. Now for the tools. The Bit.— People talk glibly of a solder- ing " iron," when they ought to speak of a sol- dering "copper." Workmen know it as the soldering "bit." Figs. 1 to 3 show the three forms in which it is generally obtainable, and the one I prefer whenever it can be used is the hatchet-shape shown last. By the way, the "Tinol" firm sells a telescopic bit of the hatchet shape which will answer most small requirements. The bit is simply an iron rod with a shaped piece of copper at one end and a handle, generally of wood, at the other {see Fig. 4). The "Fluxite" firm also have a good collapsible bit {see Fig. 4a). 127 Bit for Internal Soldering, etc. Fig. 3. — Hatchet Soldering Bit Every Boy His Own Mechanic A bit must be heated to a temperature slightly higher than that at which the solder will melt, and the young mechanic sometimes has difficulty in finding just the right source of heat. The kitchen fire fouls the bit ; the heat of the gas-ring is not concentrated enough and the bit takes too long to get hot. The flame of a spirit lamp can be used for heating the bit, but this again is a trifle slow. If you have what is known as a bunsen burner (Fig. 5) you might make that serve. An incandescent gas burner is really a bunsen burner, and if you possess one of the Fig. 4. — Telescopic Bit SCR£VVE.D JOINTS' Fig. 4a.— Collapsible Bit E^ old-fashioned upright kind, you could take off the mantle together with its prop, turn the gas on full, light up, and then have a fair-sized smokeless flame in which, if you are ingenious, you can support the copper bit while it is heating, but we fear that at the best it will be a very in- convenient method. The tool shops sell special stoves for heating bits, some of them burning gas, and others of them charcoal, but not many amateur solderers would dream of buying one. Fortunately many readers will have already in their house a quite excellent stove for the purpose, and until thev read of the fact in this place will 128 Soldering be unaware of it. Hundreds of thousands of gas-heated laundry irons are now in use, and if the ladies of your establishment possess one, do your best to borrow it when you mean business in the soldering line. In the writer's experience, one of these irons has proved a most excellent heating device. Connect up the iron by means of a flexible tube to the gas-bracket, turn the gas about half on, light up, lift up the handle of the iron, and insert the bit so that the flame plays right on to the \rt Fig. 5. — Bunsen Burner copper. There is still another method possible if you have a gas-heating stove (not a gas-cooker) in your house. Lift out some of the asbes- tos clay, and rig up the copper bit on a couple of bricks or on anything else handy and fireproof, so that the bit is held right in the top part of the flame. A small bit can be well heated in the blue flame of a "Primus" oil stove. I have dwelt somewhat at length upon the means of heating the bit, because I have found that it is the first big difficulty that the amateur solderer comes up against. If you simply took two pieces of tin plate just in the state you might happen to find them in, and then with solder and the copper bit just as it comes from the shop tried to solder them together, you would meet with more or less complete failure. Although you might not know it, judging from appearance only, the work and the bit are dirty, and the solder when melted will not flow over or J 129 Every Boy His Own Mechanic " wet " or " tin," as it is termed, any unclean surface. So don't forget that when a job has to be soldered, the very first thing to do is to scrape it clean, using for the purpose an old knife or a file. The bit, which is expected to convey the solder to the actual spot where it is required, must for the same reason also be scrupulously clean, and before starting work it is customary to tin it, that is, actually to coat it with the solder. Plenty of people fail in such a simple job as this just because they will not take the necessary trouble to get the metal nice and bright. With a file go over it until the whole of its sur- faces resemble new metal. Then heat it to what is known as a dull red, quickly rub it over again with a file, and apply some " Tinol " to it, rubbing the bit on a piece of clean tinplate, so that the solder flows all over it. If using stick solder, dip the bit, after heating and cleaning, in the flux, and then rub the solder on it ; or, better still, get a small block of sal-ammoniac from the oilshop, and, after heating the bit, rub it on the block (Fig. 6), touch the bit with the solder, and you will see it immediately flow over the surface of the metal. You will not care for the smell of the fumes that will arise from the sal- Vl'i'i'i'i'lT'' lllllll'i'lllli'ih Fig. 6. — Tinning a Soldering Bit in block of Sal-ammoniac ammoniac. 130 Soldering Patching a Vessel. — Now we have tinned our bit and are ready to do some useful work. It is more than likely that the lady of the house has a tin-plate saucepan, kettle or dish that is in need of repair, and will be only too delighted to allow you to try your " 'prentice " hand upon it. As a typical soldering job, let me assume that you are going to cover a hole in a tin-plate vessel {see A, Fig. 7) with a neat little patch which we can readily cut with some stout scissors from a new coffee tin or anything else of the sort. Scrape around the hole in the vessel and make it nice and bright {see b). Then place the little piece of tin plate so as fairly to cover the hole (c), and with the point of a nail scratch the outline of the patch upon the work {see d) ; remove the patch, and by means of a bit of wood or the point of a bradawl apply some " Tinol " thinly all over the place and slightly beyond where the patch is to go. Then replace the patch as at c. In the meantime the soldering bit has been getting nicely hot in some one of the ways I have already de- scribed. Let it rest well on the patch with the object of transmitting as much heat as possible, and move the bit 131 Fig. 7. — Stages In preparing a Soldered or Sweated-on Patch Every Boy His Own Mechanic about so that every part of the patch comes under the influence of the heat. The job is done. The patch has been "sweated" on and with reasonable care the result is a good one. But probably you will not be satisfied. You will want to see the solder in a nice ring all round the patch. There is no reason why you should not, and the extra solder will be extra security. See that the bit is nicely hot, but not so hot that the tin upon it has been badly discoloured and burnt. If it has been, give it a touch with the file, rub it on the sal-ammoniac, and apply a little solder to its face, thus re-tinning it. Then transfer the bit to the Fig. 8. — Mouth Blowpipe edge of the patch, and apply a ring of " Tinol," and with the soldering bit in perfect condition gently wipe it round the edge of the patch. If you are using stick solder, you will need first to ring the patch with " killed spirit," and then apply bit and solder together. When you are a little more experienced you can experiment with the object of lifting up a bead of molten solder on the point or edge of the bit and transferring it to the work exactly where it is wanted. It is all-important when using stick solder to hold the work in such a way that the solder can run downhill to the spot where it is wanted. Many a boy has tried to make the solder climb the handle of a kettle, whereas if he had remembered that water always runs downhill he would have saved himself some 132 Soldering Fig. 9. — The three Cones or Zones of a Blowpipe Flame annoyance and have had the pleasure of pro- ducing a result of which he could have been proud. Soldering: with the Blowpipe. — Not all soldering is done with a soldering bit. Some of the neatest and cleverest work is executed by means of the mouth blow- pipe which is simply a bent tube of glass or metal shaped as in Fig. 8. This blowpipe is used for directing a tiny jet of flame upon a speck of solder resting on the spot that has to be soldered. The flame of a candle or spirit- lamp when directed and assisted by the mouth blowpipe becomes hot enough to melt solder most readily, as a single experiment would prove. In using the blowpipe {see Fig, 10) a good breath is taken in, so filling the lungs with air. The blowpipe is applied to the base of the flame, and a gentle but constant current of air blown through it. It will be seen that the candle ^^^''^'^'^'/^'" flame has three parts or zones {seeFig.9). That at the base marked x is the coolest of them all, and in a dark room would be almost invisible. -Using Mouth Blowpipe with Spirit-lamp Flame '33 Every Boy His Own Mechanic The next zone marked y gives forth more light than either of the others. The tip of the flame marked z is the hottest of the three, and it is this part of the flame that does the work. You must try in using the mouth blowpipe to breathe through the nose, and at the same time keep the cheeks full of air, and a steady current passing through the blowpipe. A good flame will be of a bluish colour with a yellowish or brownish tip. Blow- pipe soldering comes in so useful when the job is too small for the soldering bit. Say, for example, you wish to attach the head of a pin to a coin. Clean the spot on the coin where the junction will come, and also the head of the pin. Touch both of them W^"''" ^ with the "Tinol." and, supporting I them on a piece of charcoal or brick, direct the flame on to them with a blowpipe one at a time. This "tins " them, that is, it coats them with solder. Leaving the coin where it is, Fig. U.—An easily-made hold the pin on the end of a strip of wood, and place its head in position on the coin exactly as it is to be when soldered. Then a touch with the blowpipe flame will unite the two. Fig. 11 shows how easily a spirit lamp for blowpipe soldering can be made. The wick tube is any small piece of tube available, and it slides fairly tightly through a hole cut in the lever lid of a small "self-opening" tin box. The wick is of loose threads. Note the small holes at the top of the wick tube ; they considerably im- prove the action of the lamp. Methylated spirit is the fuel. Lamps on this principle can be bought ready made. 134 Soldering Silver Soldering. — So far, I have talked about soft soldering only, that is, about solders that melt at the comparatively low temperature of a black-hot iron, but there is such a thing as hard soldering. The joints in a really good piece of silver-work or in a well-made model engine or boiler are hard-soldered, for which purpose an alloy of tin and lead would be of no use whatever, and recourse must be had to an alloy of silver and brass. Take my advice and if you use silver solder at all buy it ready made. Such a little bit will go such a long way. Buy it in the form of very thin sheet and with a pair of very strong scissors, or, if you have them, with a pair of snips, cut the sheet up into tiny squares Fi^- 12.— Gutting up Silver .^ -^ . ^ Solder into Paillons about ^ in. ( see Fig. 12 ). These are known as "paillons," which you may care to know is a French term. The flux for silver soldering is quite different from that you have already used. It is made by taking a piece of lump borax, moistening it with water, and rubbing it on a piece of slate until a thin paste is formed. Fig. 13 (p. 136) shows the outfit. If you ever try to build a model boiler or engine, you may need to make a joint in a tube or to solder the end into a tube (see Fig. 14). The surfaces having been scraped perfectly clean should have some of the borax paste ap- plied to them with a brush, and then, with the same brush, the tiny paillons of silver solder are placed in position all along the joint. Now slowly heat the work in the blow- pipe flame, but do not at first let the flame fall upon the solder. The latter should not be melted until the metal I3S Every Boy His Own Mechanic all round it reaches the temperature at which the solder becomes liquid. This course will serve to dry the borax, and the bubbling up may move some of the solder which will need to be pushed back into place. As the bubbling of the borax ceases, slightly advance the flame, and in due course the solder will melt and run into the joint, providing the work is held at such an angle that it is natural for the solder to run that way. Do not imme- diately remove the flame, but let it remain for a few 0^ Charcoal Block setioPlasrer Wafer Bowl BiOWpipi Scraper Fig. 13. — Outfit for Silver Soldering seconds so as to cause the solder to sink right into the joint. Let the job get cold slowly, and then clean off the borax by placing it in a pickle made by pouring a tiny glass measureful of sulphuric acid into twenty times the quantity of water. By the way, never pour water into sulphuric acid, or the acid will spurt, and if it falls upon your hands or face you won't forget it in a hurry, and should it fall upon your clothes you can depend upon it that it won't do them any good ; probably some of your experiences in the chemistry lab. will be fresh in your memory, and my warning may be unnecessary, 136 Soldering I have described only one of the methods of hard or silver soldering because the process is well-nigh essential in serious model building, but I think I ought to warn you that it has difficulties all its own, and that to become an expert silver-solderer demands a lot of practice, and FJam cii'sc Solder /nside. ( 'Binding ffire f/on^rd Disc Inside Method Fig. 14. SecOoto of finished f^^^M/ Tube Outside Method Silver Soldering ends into Tubes, especially applicable to Model Boiler Building there is a great deal more to be said about it than I have ventured to bother you with in this chapter. I prefer to occupy my space with information on work that is within nearly every boy's capacity, as measured in equipment and skill. 137 MAKING SIMPLE WOODEN TOYS I WANT to show you in this chapter how to make three wooden toys (all of them designed by Mr. I. Atkinson, to whom I am much indebted), which should be well within your capabilities. There is not a really difficult bit of work in any one of them. A Toy Gymnast. — One of the happiest toys I have seen for a long time is the toy gymnast, a photograph of which is given in one of the plates accompanying this book. Turn to that plate for a moment, and I will show you how the gymnast works. The figure or puppet is of thin, flat wood, normally hanging with his hands above his head, and the string which supports him is arranged as shown in the plan and elevation. Figs. 1 and 2 here- with. Normally the string is crossed, but when the lower ends of the levers are squeezed together by the fingers the upper ends are forced apart, the string is pulled taut, and the figure is jerked upwards in a most realistic manner. There is no end to the contortions and amusing positions of which the gymnast is capable, and when the maker of the toy here described sent it to me I very soon discovered that both juniors and seniors took a huge interest in its antics. The toy, which seems to be still a novelty, al- though a very old one, consists of a base, a post, a cross- piece, two upright levers, the string, and the figure. 138 Making Simple Wooden Toys u± W?3 y — T" Fig. 1.- — Plan showing how Toy Gymnast is suspended Figs. 3 and 4 are front and side elevations of the wood- work, the levers being shown broken to economise space. We Avill deal with the parts separately, and make all clear as we go. In the first case, a fairly hard wood should be used. The levers need to be of tough stuff, or some careless body will sooner or later break them. For the base a, post and cross-piece, you had better use mahogany, oak, walnut, or other hard well-seasoned furniture wood. The base should not be less than f in. thick, and 4| in. or 5 in. long by 3J in. or 4 in. wide. A hole is bored in its exact centre to take a dowel (shown in dotted lines at the bottom of Fig. 3), which runs up into the post or pillar b. This post is about | in. square and about 5| in. high, and it carries at its top a cross-piece c shaped as in the detail plan (Fig. 5), where full dimensions are given. The connec- tion here, also, is by means of a dowel, as shown, for which a hole will need to be bored with a twist bit and a suit- able piece of round rod prepared and well glued in. An excellent alternative to the dowel would be a stub-tenon at each end of the pillar, with a mortise in base and cross-piece to correspond. 139 -Front Eleva- tion of Toy Gymnast Every Boy His Own Mechanic The exact shape of the cross-piece is of importance, inasmuch as this part is a fulcrum on which the levers work. You will recognise the levers as belonging to the " first order." The horns of the recesses in the cross- piece keep the levers upright^ but you will note that the ^. J C t 13 /} =1 T O Figs. 3 and 4. — Two Elevations of Gymnast's Stand bases of the recesses are not quite flat, but there is a little projection in the centre on which the levers can be rocked a trifle. You will understand this more clearly from Fig. 6, which is a large-scale detail section from which it will be apparent that the lever d is free to rock a little on the cross-piece c. The levers d are shown in a number of the views. Making Simple Wooden Toys They are 16 in. long, | in. \vide, and f in. thick. At a distance of 5| in. from the lower end a hole is bored through the thickness to take a wire nail — a fairly stout one, about 1 J in. long. The nails must not fit the holes in the levers tightly, and the holes must be countersunk to take the heads of the nails. Preferably, also, the holes should widen out towards the heads of the nail so that the lever can rock easily. At I in. from the top of the lever are two fine holes | in. apart to take the string, as shown by the dotted lines in the detail plan (Fig. 1). rLS) 1 •s T ' - o c Fig. 5.— Pla for Toy n of C Gymn rossbar ast Fig. 6. — Diagram showing how Levers rock on Crossbar The figure or puppet must be made of tough wood, preferably not more than ^ in. thick. The kind of pear- wood used frequently for cheap set squares is one of the best materials for the purpose. The figure is in five parts — the head and body, two legs, and two arms, and it can be ornamented with ink or stain or with a touch or two of paint. The pattern for body, leg, and arm respectively are given by Figs. 7, 8 and 9. There are two holes in the body, one hole in each leg, one in each shoulder, and three in each hand. The leg and shoulder holes take the wire pivots. The largest of the three holes in the hand^ — that 141 Every Boy His Own Mechanic shown by the little circle in Fig. 9 — takes a tiny piece of matchstick {see e. Fig. 2), which keeps the hands apart and assists the action of the toy. The two fine holes in the hands take the string, which actually is a piece of fine, but thoroughly good catgut (an " A " violin string a few inches long), which should be threaded through and tied exactly as shown in the detail plan. Fig. 1. It is wise to drill all the holes before cutting the pieces to shape. There is one point of particular importance in assemb- ling the figure. Fig. 7 shows in dotted lines the exact positions of the arms. Their length and position on the body should be such that when the gymnast is raised above the catgut his body can come forward over the string and between his hands, trailing his legs after him. The parts of the body can be shaped with fretsaw and knife, and cleaned up with glasspaper. The pivots are pieces of wire, such as fine hairpin, on which " heads " have been formed by making tiny loops by means of fine-pointed pliers, these loops being bent at right angles to the wire and flat against the body of the puppet. In making these pivots, the head, as described, would be formed on one end of the wire, the leg, body, and second leg threaded up, the wire cut off to within about I in. or so, and a second head formed and bent over. The arms are put on in the same way, but between each arm and the body is a small bead (slightly thicker than the wood of wliich the puppet is made) threaded on the wire as indicated in Fig. 2. If these beads are omitted, it will be found that the legs will be continually getting jammed between the arms and the body. The distance 142 Making Simple Wooden Toys piece E (Fig. 2) will not be glued in until the arms have been threaded to the body. You will need a little help in the suspension of the puppet. Holding it upside down with the holes in the hands opposite those in the levers, thread the two ends of the gut straight through lever, hand, hand and lever, without any crossing, and tie the ends together ; then, ■-,'-.8- A- ' Fig. 7.— Body Pattern Fig. 8.— Leg Pattern Fig. 9.— Arm Pattern when the figure is allowed to drop, the gut will cross exactly as shown in the detail (Fig. 1). The best finish for the toy is a good coat of varnish, but there is no reason why you should not paint it in some attractive colours if you so wish. Varnish or painting should be done before threading together the parts of the figure or suspending it in place. A Toy Aeroplane. — You will reaUsc at once that the aeroplane shown in the plate already referred to and in side elevation and plan by Figs. 10 and 11 is not a model 143 Every Boy His Own Mechanic but merely a toy, which, by means of a string tied to a ring in front of the propeller, can be pulled about by your small brother and sister, who will occasionally have the joy, should the speed be great enough or a wind be blowing, of seeing the propeller revolve. The toy consists chiefly of the body a with rudder b, propeller f (we ought Fig. 10. — Elevation of Toy Aeroplane t- / ^ ::^ Z'-^'r/'^ Fig. 11. — Plan of Toy Aeroplane really to call it a tractor, I suppose), with planes c and E mounted on an axle d to the ends of which are screwed wheels. I show how the whole of the toy can be made in wood, which will look all the better and be all the more pleasing to its owner if brightly painted. Let us take the body first. It is 9^ in. long. If in. high, and its greatest thickness is 1| in. It is shaped with 144 EASY TOY MAKING / ^y A Toy Gymnast {See pages 139 to 143 for Working Diaivinos) A Toy Tank {See pnges 14S to 151 for Working Draw'iiigs) 1 1 A Toy Aeroplane (Sfr piiges 144 Ai 147 /.T ]\'iuinng Draiviiigs) For iiifoniiation on nniliing these toys, see pages 13S to 152 Making Simple Wooden Toys saw and plane or knife. You will see that, as illustrated, it tapers at the tail end, where it is only f in. square. At its front or nose, where the propeller is attached, it is about I in. square. These dimensions will be found to give a good effect, but if you can improve upon them, or if you have some stuff at hand of other and equally convenient size, I see no objection to your making any reasonable modifica- tions that occur to you. For example, if you were making two or three toys of this sort, you might wish to save time by keeping the body of the same width from front to back, and you could easily cut two bodies out of a piece of f-in. stuff, roughly 10 in. long, and 2f in. wide. A slant- ing cut, as shown in Fig. 12. — Cutting two Aeroplane Bodies from one piece ■f^ 2"t vk U A Fig. 13. — Setting out Rudders J\. Fig. 14.— Setting out Planes Fig. 12, would make two bodies from such a piece. Simi- larly a strip of three-ply stuff, 3 in. wide, could be divided up, as shown in Fig. 13, and cut up without wasting a bit of it into rudders, which could be left pointed or could be easily rounded with a knife. The rudder is only such in name. As shown at b, it is simply a piece of flat wood (three-ply is the strongest for the purpose) glued and nailed into a slot or notch sawn in the body. Suitable dimensions are shown in the K 145 Every Boy His Own Mechanic illustration (Fig. 10). Note that the fish-tail shape keeps the rear of the body off the ground. Just in front of the rudder b is the elevator plane e, about 3 in. long and 1 in. wide, made of three-ply stuff, and glued and nailed to the body. As for the front planes c, these are 8 in. long and 2 in. wide, and the thickness can be about J in., but any three- ply stuff can be used, and a strip of it, 2 in. wide, can be economically set out and sawn up, as in Fig. 14. System in setting out means economy when you are making two or three toys of the same pattern at one time. The lower plane is nailed to the axle below it, and also to the under- side of the body above it. But before the nailing is done, holes need to be bored through both planes to receive the vertical struts which support the upper plane. I show only three such struts, but more would look better. They may consist of wooden rods about ^ in. thick and about 3 in. or 3| in. in total length. They should fit the holes in the top and bottom planes tightly, and be glued in place. The axle should be about 5 in. long and | in. deep. The shape and thickness do not matter, but the shape given in Fig. 15 may be adopted if you like. At each end of the axle is a wheel which may be of cast iron — a type that can be bought at many ironmonger's shops very cheaply indeed — or the wheels may be cut from cotton reels or from any cylindrical wood. The propeller f (Fig. 10) should be set out on a piece of three-ply to a length of 5 in. {see the pattern, Fig. 16), and width of | in., and cut to shape with saw, afterwards cleaning up with glasspaper. Two pieces of wood or 146 Making Simple Wooden Toys metal of the shape shown in Fig. 17 can be joined together at right angles to give a good effect. We must remember that, as I said before, this aeroplane is merely a toy, not a model, and therefore should not be finished model-fashion. It is for the use of a little child, and the grey paint which in your eyes would make it so much the more professional is not to be thought of. Rub over all rough edges and surfaces with glasspaper, give it a second rub- l«-/^-^ i, t' o Fig. 15. — Front Elevation of Toy Aeroplane Axle Fig. 16. — Wooden Propeller Fig. 17. — Pattern for Metal Propeller bing with a finer paper, dust it, and then paint it in some attractive colours, making the rudder, the axle, and the pro- peller of different colours from the body. Two or three sample tins of the well-known enamels which can be bought very cheaply will enable you to arrive at some startling effects, which will give great joy to the small person for whom the model is intended. A Toy " Tank." — A substantial, if by no means pretty, toy is shown in the third photograph on the plale already referred to. This toy is as close a representation of its dreaded original as an article constructed almost whoUy of wood, and intended merely as a plaything, can be made. There are no travelling belts which would render the toy more realistic, but these belts would be only in the way on a toy for a little boy's use, and had 147 Every Boy His Own Mechanic best be omitted. However, you can exercise your in- genuity if you so wish, and easily devise an arrangement for carrying the belts if you think tlie trouble and expense are worth it. Fig. 18. — Part Elevation and Part Section of Toy " Tank" Fig. 19.— Plan of Toy " Tank " with Cover of Middle Cabin removed You will be able to get all details of the construction of the toy from the part elevation and part section (Fig. 18), and from the plan (Fig. 19). In the first of these diagrams it is assumed that the front side has been re- moved, and in the second that the cover of the middle cabin has been taken off. The actual centres and dimen- sions for setting out the sides are given in Fig. 20. 148 Making Simple Wooden Toys Let us consider the sides first. Each is a piece of stuff at least | in. thick (it might be even thicker), not less than 3^ in. wide or less than 7| in. long. As the exact shape or contour is such a big factor in the toy, you had better take the trouble of setting it out on a piece of cardboard first, and you can then cut the card- board carefully to the outline and use it as a pattern or template for laying down on the wood. Some boys are remarkably good at catching the proportions and general Fig. 20.— Setting out Sides, etc., of Toy "Tank" shape of an outline, but most readers will need the assist- ance of the diagram given in Fig. 20. Draw the base line, and then set up the perpendiculars a and b, which are 6 in. apart. The centre c is 2 in., and d is 1 in., from the base line. Join c and d. Setting your compasses to a radius of | in., strike arcs from d and c, and from these draw slanting lines to the base line as shown. Bisect the line c D by means of the line e, which, of course, will be at right angles to it, and continue e right through the base line and mark a point at a distance of 41 in. below c d. This is the centre for the top curve, which should be drawn in so as to connect up the circular ends. The oblong piece shown in Fig. 20 is one of the side cabins. 149 Every Boy His Own Mechanic The pattern or template should be laid down upon the planed wood, and a line pencilled round. A bow saw would cut the curve quite well, but if you do not possess one you must do the best you can by nibbling off bits here and there with an ordinar}^ saw and afterwards shaping with knife and chisel, finishing with coarse, medium and fine glasspaper in the order given. One face of the wood you are using is probably better than the other, and it will be well to lay the pattern on upside down when marking out the second side, so as to ensure that the parts of the sides that show have the best possible appearance. On each side is nailed a little cabin, of which Fig. 21 is the inner elevation and Fig. 22 the cross-section. You will note that the gun is suspended so as to move slightly when the " tank " is pulled along. Each side cabin consists of one piece of wood, 2| in. by If in. by | in. thick, and in each are bored two holes. One of these holes is bored from the inside face, and has a diameter of 2 in. Really it is a recess going only about three- quarters of the way through. The other hole is simply a gun port through the front of the cabin to connect with the recess. I have mentioned the two holes in this order, but, as a matter of fact, in boring it would be better to make the small hole (| in. or | in. in diameter) first, and then cut the recess with a big centrebit. The precise size of the recess is of no importance. Of course, in making the two side cabins you will recognise that they must be a pair ; in other words, one must be made on a different " hand " from the other. The dummy guns are pieces of round rod suspended 150 Making Simple Wooden Toys by a wire in such a way that they can roll quite freely. Tiny screw-eyes can support the wires, or small holes can be drilled and a looped wire inserted and clenched over on the top. The side cabins should not be nailed on until the inside cabin and the bottom have been fixed. The " tank " is held together by means of a bottom f and centre cabin g h, to which the sides are nailed. The bottom F is 2 in. wide, from | in. to f in. thick, and about 9 in. long. Two holes can be bored through the back Fig. 21. — Elevation of " Tank's " Side Cabin, showing Inner Side Fig. 22. — Cross Section through "Tank's" Side Cabin part as shown, but their only purpose is to lighten the appearance. On the bottom are nailed back and front walls G and h to the centre cabin. Their height is If in. or 2 in., and the width must agree with that of the bottom. In the front wall is bored a hole through which the dummy gun projects. The top or cover to the cabin is a piece of similar stuff to the walls, 4 in. long, and a recess is bored in its underside to give play or freedom to the dummy gun J, which swings to and fro. The gun is of round rod, and suspended on wires in the manner illustrated. The cover is nailed down on the cabin walls. You will take great care that in putting together the " tank " you get the bottom slightly on the slope. The 151 Every Boy His Own Mechanic amount of the slope will largely depend on the size of the rear wheels you are using, and it should be sufficient to give clearance to the wooden roller l, which works between the sides, and is pivoted on two wire nails. The back wheels are mounted on a stout wire, roughly 3 in. long, or a wooden axle may be nailed or screwed to the bottom if preferred. >52 PAINTING, ENAMELLING, AND STAINING Painting. — Most things that you make in wood need to be finished with a coat of paint or varnish. Anybody can put on paint, say you. Yes, I think anybody can, but what is necessary is to use the right kind of paint and put it on properly. Now, the first essential is a good brush. A little more money spent on the brush at the start and a little more care taken with it in use will mean far better work than can be done with a poor brush, which will lose its hairs continually as the painting progresses and will leave the painted surface covered with ugly brush marks. What the painter calls a " fitch " with hog-hair bristles, a flat brush of the same material, a good-quality sash tool — that is, a brush specially shaped for painting narrow sash bars, etc. — an oval brush or either of the last-named " ground," that is, bevelled to an edge — any of these is an excellent paint brush for general use, and you can work wonders with a small and a large sash tool. When you get a new brush, and you have some rough- and-ready work waiting to be done, you can go straight ahead with it, because the rough painting will do the brush a lot of good, and get it into condition for better jobs. Workmen often get a new brush into condition by using it for a day or two for painting brick walls. 153 Every Boy His Own Mechanic Do not forget that when the job is over and if the brush is not to be used again for some time, it should be rinsed out in turpentine to remove the paint and then thoroughly well washed with soap and water — very little water at first, but plenty of soap, afterwards increasing the water until the soap lathers freely. Next, the brush should be rinsed out under the water tap, shaken free of water, allowed to dry, wrapped up in paper, and put away till wanted. If, on the other hand, the brush will be wanted for use next day, keep it with just its bristles, and only the bristles., immersed in linseed oil or in a mixture of linseed oil and turpentine, tying a string round the handle and so suspending the brush that the weight does not come on the bristles. Should the bristles be mounted in tin or other metal, always keep the metal out of the liquid. A new brush of the quality used by a workman is too long in the bristle for use, and it is customary to tie string round the bristles at the part where they are secured to the handle so as, in effect, to make them shorter. Then, as they wear down, the string is undone turn by turn. I do not suppose, though, that you will take the trouble to do this, but always remember that the professional painter gets his good results very largely because he is willing to spend time on such details. Any pot will do to hold the paint, and nowadays the best oilshops, and, of course, the decorators' supply houses, sell paint put up in cans having very convenient handles so that the can itself acts as a paint pot. Mixing up your own paint is probably out of the question. You will buy a good quality ready-prepared 154 Painting, Enamelling, and Staining paint, which, believe me, is far superior to anything you can make at home. But as I like to explain the why and wherefore of things as I go along, I may explain what an oil paint actually is. It is a pigment — what you may know as a " colour " — or a mixture of pigments worked up with a suitable liquid so that it can be spread over the work to be painted. Very frequently the pigment has a metallic base, for examples, white lead, red lead, zinc white, red oxide of iron, etc., or it may be a coloured earth, such as ochre, umber, etc. The principal liquid in the paint is linseed oil, or similar oil, which, when drying, forms a tough elastic coat which protects everything it covers from the effects of the atmosphere. The pigment gives some protection also and supplies the colour. To make the paint workable and to give it a nice consistency, turpentine is added. A further ingredient — the driers — may be added to assist the paint to dry quickly, but you will remember that the drying of paint is not like the drying of a wet coat. It is simply the combining of the oil of the paint with the oxygen of the air, and not a simple evaporation. On new wood paint has a way of sinking in, and leaving a very unsatisfactory surface, and no amount of daubing on the paint at the outset will get a really good effect if only one coat is used. If you have made a kennel, a cupboard, or a boat, and have put some weeks, or per- haps months, of work into it, surely it is worth while putting in a few extra hours in order to execute the painting properly, and so I advise you not to be content with just one coat. For the first coat, use the prepared paint just as you receive it, having previously rubbed down all the ^55 Every Boy His Own Mechanic surfaces with glasspaper. Allow at least twenty-four hours for the paint to dry (it will not be really dry, but will be sufficiently hard for the purpose), and then go over the work with some putty or painter's stopping, and fill in all little holes made by punching in the heads of nails, etc. etc., using for the purpose an old blunt table-knife. The stopping is made by mixing I lb. of putty with 2 oz. of paste white lead (white lead ground in oil). Now putty, which is only whiting or ground chalk and oil, can be safely held in the hand, as it is quite harmless, but white lead, or any mixture of it. should always be held on a little board of wood, as all the lead compounds affect the human body injuriously. If you have had to do much stopping up of crevices, you had better leave the work another twenty-four hours. But if only an occasional nail-hole has had to be filled up, you can go ahead at once. Gently rub the whole job down with a piece of worn glasspaper and apply a second coat of paint, this time mixing a little turpen- tine with it. This thinning will make the paint flow more easily, and will assist it in combining with the first coat. Allow another twenty-four hours at least, and you can then give the third and final coat, this time using the paint as it is, and without any extra turpentine. Enamelling:. — Some of the nicest paint on the market goes by the name of enamel. This is really a very fine pigment or colour ground up with a suitable varnish, and I know that its use will appeal to you. Unfortunately, people suppose that enamelling is childishly easy, and they proceed to daub the stuff on where it is wanted, 156 Painting, Enamelling, and Staining and often where it is not wanted, so generously that it runs down in " tears " like so much treacle. Such sloppy work is unworthy of the boy mechanic. It is not difficult, I admit, to get a showy effect with enamel paint, but please take the trouble of preparing the work properly and of applying the enamel carefully. If your pocket affords, get a really good brush for the job, or use one that has been well broken in. Sometimes at a second- hand shop I have seen good paint brushes, one-third or one-half worn, to be had for just about the same propor- tion of their original price. Such a brush thoroughly well washed with soap and water, rinsed and dried, would make a first-rate enamel brush. If you buy a new one, get a brush especially made for varnish. Thoroughly prepare the work in the first place with worn glasspaper, and if you are intent upon getting a result of which you may well be proud you will need to buy at the same time as you purchase the enamel a tin of the special " undercoating " made by the enamel manufacturer especially for use with his enamel. Apply two or three coats of this special preparation, allowing full time for each coat to get hard, and gently rubbing each down with worn glasspaper and wiping over with a duster before proceeding farther. On such a basis as this you will get a very fine finish, and if you are out for something very special, you can apply a second coat of the enamel. Perhaps you do know that not all enamel is glossy. Some of it dries with what is known as a " flat," that is, a lustreless finish, or with the very slightest shine re- sembling that on a new-laid egg. The use of a flat enamel 157 Every Boy His Own Mechanic on a piece of furniture is generally preferable to that of the glossy kind. Always, in enamelHng, avoid dust. Don't do the work in a dusty room, and don't let the brushes and enamel lie about and get gritty. Keep everything as clean as you can. Pour a little of the enamel out into a small vessel, and use it all up before taking more from the tin. Another important point is, try to strike the ^^PPy medium by applying not so much as will run down in tears or form wavy lines, and not so little as to cause the brush marks to show and give a patchy effect. The advice is quite easily given, but there is more in putting it into practice than you might suppose. Finally, don't brush or work the enamel too much in applying it. The fewer the strokes of the brush the better. Staining^. — Now this is a very different process of colouring wood. It adds nothing to the surface, but is simply a method of dyeing the outer skin of the wood. The old-time craftsmen were very clever in concocting vegetable stains, and the beauty of their effects has never been surpassed, but nowadays only the few still go to the trouble of making their own stains, and most people rely upon various forms of aniline colours, a variety of which can be bought in cheap packet form. As a rule, directions are printed on the packets, and they amount to little more than adding hot or cold water, with perhaps a little vinegar, to the powder, although many of them (those known as "spirit soluble") require the addition of spirits of wine or the far cheaper methylated spirit, which is practically the same thing with the addition of some nasty-tasting mineral spirit to render it objectionable 158 Painting, Enamelling, and Staining to the palate. Aniline dyes can be applied with brush, or sponge, and will be found excellent for general use, although the brighter colours, particularly the reds, are fugitive— in other words, they bleach— in direct sunlight. Bichromate of potash and permanganate of potash, respectively, dissolved in hot water make fine rich stains, and coat after coat can be applied until the right tone is reached. An excellent walnut stain is made by stewing some green walnut peel in water and applying two or three coats of the liquid to the wood in a warm room. When nearly dry, give it a coat of bichromate of potash solution. To make wood resemble the tone of dark oak, apply some brunswick black considerably thinned with tur- pentine. For a mahogany stain dissolve 1 oz. of dragon's blood (a gum you can buy at an oilshop) in 1 pint of turpentine. Stand the bottle in a warm place and shake it frequently. Most of you know the term "fumed oak." The fuming or fumigation of oak is an interesting process, but not all oak is susceptible to the action of the ammonia used for the purpose. Some varieties of mahogany also can be treated in this way. To find out whether a piece of wood can be darkened by fuming, place a portion of it over the mouth of a bottle containing liquor ammonia (the so-called " hquid ammonia "), the stopper having been removed. If the wood is susceptible, its colour will soon darken. The work must be quite clean from grease or the marks of the hands. If you are using a good-sized packing case as the fumigating apartment, place a saucer- ful of liquor ammoniae on the floor of the case, then insert »S9 Every Boy His Own Mechanic the articles, but not so that they touch the liquid, close the lid, and stop the joints by pasting on strips of brown paper. The longer the wood is left in the case the darker will it become. Wiping over with diluted liquor am- moniae will have a darkening effect upon any wood that is susceptible of the other treatment, but the true fuming method has one great advantage over the use of liquid stains — it does not raise the grain of the wood. Generally, after the use of a liquid stain, it is necessary, if a good finish is required, to go all over the work with glasspaper to remove the portions of the wood fibres swollen and raised by the liquid. The oilshops sell a mixture known as " combined stain and varnish," and you may be tempted to use it. It may do for a common job, but not for anything which you prize, as the effect is rather cheap and nasty. The boy mechanic may be entrusted with the job of staining a floor margin, and may resort to the stuff as being the easiest and quickest for his purpose, but he will get a far better effect and a more lasting one by getting some oak, walnut, or mahogany stain in liquid or powder form, giving it twenty-four or forty-eight hours after appli- cation to get dry, then applying a coat of size, and finally a good flowing coat of oil varnish purchased from a reliable firm. :f*o FRETWORK IN WOOD Most people associate fretwork with those fantastic and often fragile articles which sometimes ornament cottage parlours — photograph frames that dwarf the photographs, model " tanks " and locomotives grotesque to the point of absurdity, clock cases and brackets that nobody dare dust, and so on. Fretwork has suffered from two causes — poor designs and their wrong application. It is restricted in its scope, but the zealous fretcutter has not recognised any limita- tions and has applied his ornament to any- thing and everything that can be made of wood. Fretwork can be made very beau- tiful and can be extended to ivory, celluloid and various metals. I shall give in this chapter a few designs (see Figs. 2, 6, 7, 8 and 10) that, in my opinion, will occasion but little reproach. Let me first talk of fretwork in wood, and leave the finer work in metal to a later chapter. Fig. I. — Fretsaw Every Boy His Own Mechanic Saws. — The saw may be hand or machine, the ad- vantages of the latter being greater speed of cutting, less fatigue, and freedom of both hands to guide and control the work. Suitable machines are shown in variety in any dealer's catalogue. In use keep the machine clean and oil all the bearings often but sparingly; a suitable lubricant is cycle oil of a thick variety. The hand saw may resemble Figs. 1 and 3, or may be one of the many other patterns available. The sweep of the frame should not be less than 12 in. or more than 18 in. In selecting a frame, see that the clamps which hold the blade in tension are good and work well. The best type of clamping arrangement is that in which the blade is simply inserted and then tightened up by giving the handle a turn. Something quick and easy is required because the saw has frequently to be threaded through holes drilled in the work, for which reason the blade has to be undamped every time. Remember one point : so thread the blade that the teeth cut on the downstroke, otherwise the sawdust will obscure the lines of the pattern, and a swarf be raised on the paper which will make it difficult to follow the lines ; this means that the working stroke is the pull and not the push, as the controlling hand is underneath the work. When a fretsaw, usually a machine saw, cuts on the upstroke, a blowing device is employed to keep the pattern free of sawdust. With regard to saw-blades, buy the best. The differ- ence in price between the good and the bad is so little as not to be worth considering, whilst a poor, slow-cutting soft blade which soon bends or an over-hardened one that soon breaks when in use is a nuisance and may mean the 162 Fig. 2. — Design for "Oval" Frame in Fretwork {A and B show respectivdy a difficult and comparatively easy detail of forming the rebated edge) 163 Every Boy His Own Mechanic fracture of delicate detail. Rounded-back blades of the best quality will give the greatest satisfaction. Other Equipment. — Work is held for sawing by means of a cutting board, which is either per- manently screwed to the bench or fitted with a clamp for attachment to bench or table. The usual shape is shown in Fig. 3.— How to Hold a Fretsaw Fig. 4, the V-lK)tch accommodating the saw blade when at work. This figure shows a table or bench especially designed for fretworkers' use. Perhaps you can pick up a light table for a few shillings and screw on a notched cutting-board, and, if necessary, shorten the legs by an inch or two so that as you sit at your work the table-top is at such a height that your left hand easily rests upon it, while your right works the saw ^Wf| x^jj from underneath. Then, if """^ a small vice (as in Fig. 4) c^ can be attached at one end, p;g 4._Fretworker's Table with you will have a serviceable Cutting-board and Vice and comfortable bench for fretwork and similar light opera- tions; but don't attempt to use it for carpentry work, as it will not be solid or heavy enough for planing upon. 164 Fretwork in Wood Besides the usual tools and accessories — hammer, fine- toothed ordinary saw, pincers, small screwdriver, chisel, small nails or " pins," seccotine, gluepot, etc. — which most boy mechanics are almost certain to possess, you will need a special tool for drilling or boring holes in the work to give a start for the saw in enclosed parts of the design. A bradawl or even a gimlet — anything with a wedge-shaped point — will only split the work as a rule. The proper tool is the drill named after your dear old class-room friend Archimedes, its twisted stem resem- bling the famous hollow screw which the ancient Greek invented (about 260 years B.C.) for the purpose of raising water. The twisted stem rotates in a bearing formed in the handle {see Fig. 5), and is given motion by pressing down the bobbin through which the stem is threaded. The bottom end of the stem carries a chuck (vice) to hold a drill-bit. A good type of archime- dean drill has a small spring in the handle to assist the withdrawal of the bit ; another improved pattern facilitates speedy work — it carries balance weights just above the chuck, the momentum which they gain on the down stroke of the bobbin being sufficient to keep the drill rotating on the idle upstroke. Another necessity is glasspaper of three grades, Nos. 2, 1| and 1, used respectively for rubbing off pasted- down designs, cleaning up the surface and finishing the job; the higher the number of the glasspaper the coarser •65 Fig. 5. — Archi- medean Drill with Chuck or Holder to take D ri lis or Boring Bits Every Boy His Own Mechanic being its grade. The trouble in using glasspaper is that without great care you find yourself rubbing away the sharp edges of the wood and losing the effect of good workmanship. Therefore to obviate this always use the glasspaper wrapped tightly round a block of wood or cork. Fig. 6. — Design for Wall Bracket in Fretwork (The centre support is a repeat of half the bach) Fretwood. — So far I have not mentioned the material. Many firms now make a speciality of fretwood, and you can order from them exactly what you want, so avoiding waste pieces. Almost every cabinet-making wood is ob- tainable in suitable thickness — in the neighbourhood of =j'g in. — for fretwork; and the unit of measurement is the square foot. Thus, a piece of wood 7 in. wide by 29 in. long will contain 7 X 29 = 203 sq. in., nearly 1| sq. ft., and would be charged for on that basis. i66 Fretwork in Wood All fretwork is liable to warp and twist. Wood is constantly absorbing or giving off moisture according to the condition of the surrounding atmosphere, and unless it is suitably secured at the sides or held down by weights warping is inevit- ^^ able when the fibres rC^ ^. swell. Two-ply and three-ply wood has two or three layers of thin wood glued together under great pressure, one of them being at right angles to the other or others as regards the direc- tion of the grain, so that the grain of one layer counter- acts any tendency of the other layer to twist out of shape. Some good pieces of three-ply material can often Fig. 7. — Design for Frame in Fretwork be obtained from tea-chests, but the faces of the stuff need to be glasspapered into condition. The Design or Pattern. — Fretwork designs of the printed kind are obtainable on thin paper and need to be pasted down on the wood (but if they can be easily trans- ferred by means of carbon paper and a hard pencil, so 167 Every Boy His Own Mechanic much the better, and there will then be no paper needing to be rubbed off at a later stage). Let the length of the design run in the direction of the grain. Apply the paste to the design only, and use either boiled starch or an office paste of the " Fixol" or " Stickphast " types, but in any case use as little as will effect the purpose. Applying the paste to the wood itself or an excess of paste on the paper will raise the grain and pos- sibly warp the wood. Let the pasted paper get thoroughly dry before starting to use the saw. Using the Fretsaw. — The actual fretsawing is a matter of infinite care and practice, and not much need be said concerning it. Hold down the work firmly with the left hand, see that the blade is held taut in its frame, and firmly grip the handle in the right hand, always keeping the blade perfectly upright and making uniform, steady strokes. The right hand x68 Fig. 8. — Design for Letter Rack in Fretwork Fretwork in Wood simply works the saw up and down, and does not advance the saw into the wood. The feeding of the work to the saw is a matter for the left hand, and this is where most people find the machine saw to have a great advantage. It is usual to saw out the inside parts of the pattern before attempting the edges, because the work is then more easily and safely handled up to the final stages. The turning of both inside and outside corners is a matter for practice. Use fine good saws and plenty of common sense. Overlays, Marquetry, etc. — The modern fretworker is fond of overlays — fret-cut patterns in thin stuff glued down on the face of the work. Very thin stuff should be placed between waste stuff, nailed together at the edges, and the pattern laid down on the top piece of waste. This leads to double and treble cutting — known as plural cutting — only to be attempted when you have mastered the correct use of the saw — and to marquetry, which is a system of ornamentation by which very interesting effects can be obtained. Two pieces of wood of different colours, say holly and rosewood, are cut at the same time, care being taken to keep the sawn edges perfectly square, and to avoid spoiling any cut-out pieces as might be perfectly legitimate in ordinary fretwork. Then the parts of the two designs are interchanged {see Fig. 9) to give good 169 E3(kIE Fig. 9. — Marquetry Inter- change Pattern Every Boy His Own Mechanic effects, and glued down on the surfaces to be ornamented, thus forming two companion ornaments in reverse colours. Finishing. — For removing the pasted-down design do not attempt to soak it off. Fretted woodwork cannot stand water. Instead, place it on a per- fectly smooth flat surface and rub it off with No. 2 glasspaper held round a block, finishing with Nos. 1| and 1 applied suc- cessively. By inclin- ing the saw- blade inwards when cutting out a piece (a circle, say, or other simple figure), the area of the bottom face of the cut-out part will be made greater than that of the top of the hole from which it came {see the section, Fig. 11), and by seccotining the edges and possibly further securing the part from the back it will be possible to mount the cut-out part as a bevelled-edge 170 Fig. 10, — Design for Frame in Fretwork Fretwork in Wood overlay entirely covering the hole. But good workman- ship is absolutely essential, as the bevel must be uniform. In straight-sided patterns, some workers obtain a uniform bevel by wedging up the fretwork slightly Fig. 11, — Diagram showing the Use of Bevel-cutting in Appliqufi or Overlay Work at one side, the saw blade being kept perfectly upright, but should the wedges slip the bevel alters. Some fret-cutting machines have a tilting table which facilitates the cutting of bevels. Fire-screens can be well decorated in this manner. 171 GLEANING AND ADJUSTING A BICYCLE I TAKE it for granted that nearly every boy knows a great deal about his bicycle, and that in a chapter under the above heading he will look for information only on those points in which his acquaintance with his machine is not likely to have afforded him experience. Still, there are one or two matters, such as the repairing of a punc- ture, which I must dwell briefly upon, although to many my readers instruction on that point will be super- fluous. I shall take the case of a bicycle that has been running two or three years^ or which has come secondhand into your possession, and which would be all the better for a complete overhauling. True, the professional cycle repairer could probably do the work better than you can, but in taking your machine to bits, its mechanical anatomy will be impressed on your mind in a way you will never forget, and you will the better be enabled to remedy any trouble that might occur on the open road. The Parts of a Bicycle. — Every part of a bicycle has its own particular name. Look at Fig. 1, and you will at once identify the chief of its components — the top tube 1, the down tube or seat tube 2, the bottom tubci 4, and the head tube 3. In addition, there are the front fork blades 23 and the back fork blades 15. There are the front and rear wheels with rims 19, tyres 18, 172 Every Boy His Own Mechanic spokes 16, valves 17, and spoke nipples 24. To protect the rider from mud and dust, there are the front mud- guard 27, with its extension, and the rear mudguard 26. In the bottom bracket (at the junction of the seat tube and bottom tube) is the spindle, behind 35, carrying the chain wheel 21, the chain 20 transmitting the drive to the chain ring on the hub of the rear wheel. The handle- bars 7, with handles 8, are one with the steering tube which is clamped into the fork stem, this being a tube passing through the head tube 3 ; the lower end of the fork stem carries the fork crown and fork blades. The saddle 12, and tool wallet 13 are supported by the seat pillar 11, which enters and is clamped within the seat tube 2. In the bicycle illustrated are two rim brakes, both operated by hand ; 10 is the front brake forket and 25 the back brake forket, but, as you know, some bicycles have only one rim brake, and in addition a brake working within the rear hub and actuated by the chain when back pressure is applied to the pedals 22. In my opinion, no safer system of brakes has yet been devised than the hub-contained type, but there should always be a front rim brake as well. Gear." — Most boys will recognise the gear change control lever 28, and its cable 29, but I find that the general idea of what is meant by the " gear " of a bicycle is a very vague one, as well it might be. It is a term that dates back to those days when our fathers — in some cases our grandfathers — rode the "ordinary" machine with a big front wheel and a small back one. If that front wheel was 60 in. or 56 in. or 64 in. in diameter, then the gear of the machine was said to be " 60-in./' " 56-in.," or " 64-in." 174 Cleaning and Adjusting a Bicycle respectively. The distance travelled in one revolution of the pedals in those old front-driver machines was 3l times the diameter of the front wheel ; thus a 56-in. wheel travelled about 176 in. for every complete revolution of the pedals. Now, if you have a bicycle and by careful experiment find that one complete revolution of the pedals drives the machine forward 176 inches, you will know that your bicycle has a " gear " of 56, but it is an awkward experiment to carry out, and it is much more simple to work a little sum instead. Fig. 2 will show you how to set about it. First count the number of teeth on the chain wheel. Say it is 50. Take the diameter in inches of the back wheel ; say this is 22. Multiply the two together, 50 X 22 = 1100. Divide this by the number of teeth in the chain ring or sprocket on the back hub ; assume this to be 18. Then 1100 -^- 18 = 61 and a fraction^ and the machine is said to have a gear of 61. The higher the gear, the greater the strength required to push the machine up-hill or against the wind, and that is why boys' and ladies' machines are always geared lower than a man's. But the higher the gear, also, the greater the speed of the machine per revolution of the pedals, and the more convenient for running on a slight down- hill, or with the wind behind you. So it comes to this. Up-hill you want a low gear. Down-hill you can do with a high one. And it is this pleasant alternative which you get by installing a variable gear device or " change- speed gear," which is a box of cog-wheels built into the back hub, by means of which the leverage or mechanical advantage is increased or decreased. Whereas on a fixed gear machin o Qi) a H o cs ^ o b ^ •a pii en ^ c« '$ =« o ^ « ^ & u > o b 312 Building a Model Locomotive for the frames and footplating. Between the crosspieces c p and c p, the strip work shown at m p and c b (Figs. 8 and 8a) may be added to stiffen up the footplate and also to represent the motion ,C(> ^ ^' ■ ' T, J- i L A6 \ Axle Sidt ^ramts foot bio re 'so WheeJs plate and slide bars of the real engine. Coupled Wheels, Bogie, etc. — The detail drawings of main axle- boxes (Figs. 9 and 10) show the arrangement of the coupled wheels in the frame. By using slotted axleboxes instead of plain drilled holes it is possible to fit up the wheels on their axles and then put them into place complete, securing them by a " keep " plate (strip wood, metal or card), as shown at k. Fig. 10 is a view of the back of the engine from the Fig. 9. — Section showing Details of Axleboxes, Frames, etc. f^ 8P (eac/f) £0 ^ Foot p/oTej Ax/QboKCs Fig. 10. — View of Rear End of Engine from Underside, showing Axleboxes, etc. underside. Fig. 9 is a sectional view of the frames and front main axlebox, showing how the side frames are 213 Every Boy His Own Mechanic continued below the footplate level to a point which just overlaps the frame of the leading bogie. The latter structure is illustrated by Fig. 11. The framing consists of three pieces of card secured together by angle-blocks in the inside top corners. The spring work (equalisers, etc.) is, in this case, mere ornament applied to the out- side. To obtain the relief, the parts may be built up in layers ; for instance, three layers would make the equalisers and one and two the springs underneath. For the axle- Slot -for bm Oncjfe ' ^ blocKs equi/iyrs Fig. 11. — Details of Leading Bogie 'ax^eboKes boxes wood blocks are suggested, but, of course, four or more layers of card may be employed. Boiler. — The boiler barrel may be made out of a piece of flat card over a good round postal tube, curtain- pole or anything similar. The diameter of the boiler barrel is given as 2^ in., so that the tube bar or pole chosen should measure as nearly as possible 2| in. diameter outside. If a postal tube is employed it may, of course, be cut to length and left inside the boiler barrel to stiffen the whole structure. The front end of the barrel has an additional wrapper strip w (Fig. 8a) the width of the smokebox glued on to it. The firebox end is opened out 314 Building a Model Locomotive as indicated ; the rear end of the firebox sides f s being retained to the shape required by a flat piece of wood about J in. thick, cut out to fit inside. This piece of wood F E (firebox end) should project slightly, and the outer edge should be rounded as shown in Fig. 8a. Funnel and Dome. — The funnel and dome {see Fig. 12) are best turned out of beech or box wood to the shape as shown, and if no lathe is available the builder must rely on the help of a pattern-maker or wood turner. If turned in box or other similar close-grained Avood the Hofef>, Fig. 12. — Funnel Turned from Wood tvhirenint) Stucco Fig. 13. — Funnel Shaped from Composition saddling of the underside of these mountings may be done with the file, the base curves at the sides being modified with the same tool. The other alternative is to turn them straight down with a dowel pin out of the solid, and then to form the base curves with a stucco made of whitening and hot glue {see Fig. 13). When dry, this mixture, if there is enough whitening in it, can be carved with a penknife or filed to shape. The safety valves on the top of the dome should be of bright brass, also the whistle. Oddments may be worked up into these, or cheap dummy fittings may perhaps be bought. In referring to scrap it is always advisable for the amateur Every Boy His Own Mechanic model maker to collect odd fittmgs, old clocks, instru- ments, bits of other small machinery, etc., for future use. Tender. — The tender is a simple box structure, which is strong in itself, the side framing b s F (Fig. 3 and 14) underneath being necessary only to overlap the bogie frames and give the undergear a solid appearance. The bogie frames are shown in Fig. 15, and their attach- ment is indicated in the sectional drawing (Fig. 3). A plain pivot hole only (instead of the slot necessary in an Fig, 14. — Details of Model Tender engine bogie) is required in the case of a double-bogie vehicle. The pivot is a screw which engages in a block of wood inside the tender body. In building up the body, angle blocks of wood may be freely used to unite the cardboard "plates" forming the sides, ends, etc The coal space has a sloping bottom, and the coal rail may be built up out of wire or a strip of card may be glued on the top edge, and the rails represented by drawing wide black lines on the card to represent the spaces between the rails. Completion of Model.^ — When complete any rough edges on the joints should be trimmed up with glasspaper 2l6 Building a Model Locomotive and the whole locomotive and tender coated with size. This is a necessary preliminary to the coating of paper with oil paint, and any loose parts such as bogies should be removed. The coupling-rods may be made of wood or metal and " screwed " into the wheels ; the screws are secured by seccotine or a shellac cement. The coupling-rods on each side of the locomotive are arranged at 90 deg. to each other, not opposite. M>/e -for^'n Qn^le biociYs \.J^'^ ^ fran-t Fig. 15. — Bogie Frames of Tender The hand-rails (Fig. 16) should be made of stiff wire, the rail along the boiler being fitted into standards made of split pins. The boiler bands should be strips of card carefully cut out with a sharp knife and glued on to the boiler, the joints being on the underside. Buffers may be made of wood, small drawing pins, polished bright, forming the heads. The hooks are best made of two or three thicknesses of strong card glued together. One or two elementary hints may be given for the benefit of readers who have not attempted such an am- bitious model before. The parts should be drawn out on the card before cutting them up ; care being exercised to see that the setting out is correct. This will ensure an 217 Every Boy His Own Mechanic accurate result and good fitting of the parts. The glue should not be too thin or too lavishly used. One pro- fessional expert in cardboard modelling known to the writer strongly advocated gum arable as an adhesive, saying that with this substance and by building up layer on layer, models would last at least a hundred years. (J pi it bin The gum arabic needs to be dissolved in water. Except where wood parts are employed good gum may be used ^Handrail ^'^ ^^ P^^^^ ^^ g^^^- Fig. 16.— Details of Some of the letter references in the Handrail illustrations given in this chapter have already been explained. The following is a complete list :— Locomotive : a b, axleboxes ; b b, boiler barrel ; K, keep for axleboxes ; w, wrapper for smokebox ; s b, smokebox door ; f r, smokebox front plate ; w T c, water-tube cover ; c p R, coupling-rods ; c t, cab top ; w I, whistle ; c H, chimney ; d, dome ; g i, guard irons ; c E, corner frame edging ; e d, edging of frames ; c c, cylinder cover piece ; b, buffers ; b p, buffer planks ; c p, cross pieces ; b s, back step (and front step of tender) ; M p, motion plate ; f s, firebox sides ; f e, firebox end. Tender : b s f, bogie stop frames ; c r, coal rails ; T p, tank top ; h r, hand rails ; t t, tender tanks ; t b, tool boxes ; r t, tank filler ; b p, buffer planks. 218 TURNING WOOD IN THE LATHE By A. MiLLWARD The Lathe. — A boy who owns (or can get the use of) a lathe, however simple its form, will find it invaluable not only for making any number of useful things, but also as a great help in many other hobbies. Any object having a circular form can be readily and truly shaped in a lathe, which comprises essentially a pair of "centres" between which the work is revolved against the action of a cutting tool. In order to make the instructions which follow more easily understood it is proposed to give first a brief description of the component parts of a lathe with their proper names. In Fig. 1 is shown a front view of a simple form of lathe, in which a is a foundation plate or bed carried on a bench or legs a\ On the bed a is fixed the headstock h, which carries a revolving spindle or mandrel c, which is rotated by pulleys d fixed thereon. The pulleys d are driven by a belt e passing over one of the pulleys d and over another pulley of a series of pulleys/, which are driven or rotated by a treadle g through the medium of a crank pin h on the pulley and a connecting rod or pitman ^. The variation in the sizes of the pulleys d and/ is to pro- vide a simple form of gear for varying the speed of the mandrel. It will be apparent that if the belt c is placed on the first or outer pulleys (that is, on the smallest one Every Boy His Own Mechanic of the pulleys d and on the largest one of the pulleys /), then the mandrel c will be rotated at a greater speed than would be the case were the belt placed as shown in the illustration, but the speed of treadling would remain constant. On the opposite end of the bed a, is arranged the loose headstock, tailstock, or back poppet k, which is free to Fig. 1. — Diagram of Simple Lathe with Parts Lettered for Reference move on the bed a until clamped in position. The back poppet k carries a spindle I which, on turning the wheel l^, is moved through it by a screw. A tool rest m is clamped to the bed in any desired position. The mandrel c and the spindle I are each provided with centres n, which must be exactly opposite one another in order to produce perfectly round work. Fig. 1 must be looked upon not 220 Turning Wood in the Lathe as being the drawing of any particular form of lathe, but merely typical of a simple form, as almost any lathe, however complicated, will comprise the above described essential parts. c Figs. 2 and 3. — Wood-turning Gouge Tools. — With regard to the tools required for wood turning it will be sufficient to start with a wood-turning gouge {see Figs. 2 and 3, which are plan and side views ZZ 3 •^si cEir: J Fig8. 4 and 5. — Wood-turning Chisel respectively) and a chisel {see Figs. 4 and 5, which are also plan and side views). It will be seen that the chisel, unlike an ordinary wood chisel, is bevelled or sharpened Fig. 6. — Tool Handle to be Turned in Wood from both sides, and its edge is inclined instead of being square with its sides. Making: a Tool Handle. — ^As a first attempt at wood- turning it is proposed to make a tool handle, as shown by 22J Every Boy His Own Mechanic Fig. 6. Get a piece of square wood (the most suitable will be beech, which is inexpensive and fairly hard and close-grained) an inch or two longer than the handle when finished is required to be, and of a thickness slightly Fig. 7. — Square Piece of Wood for Tool Handle greater than the largest diameter of the finished handle. Square the ends and mark diagonal lines a b from each corner, as shown on Fig. 7- At the point where the two lines cross each other — which will be the axial centre of the wood — make holes with a centre punch. Now chisel or plane away the corners c of the wood shown in dotted lines on Fig. 8, and make a saw cut d along one of the c ^.f-^ \ \ ij 1 \ 1 / / c Fig. 8. — Wood for Turning Tool Handle prepared for the Prong Chuck diagonal lines on the end to take a " prong " or " horn " chuck {see Figs. 9 and 10) which is inserted in the nose of the mandrel c {see Fig. 1) in place of the plain centre n. The prong or horn chuck, of which a side view is shown 222 Turning Wood in the Lathe on Fig. 9 and an end view on Fig. 10, is for the purpose of causing the wood to turn with the mandrel whilst being cut. Be careful to see that the centre prong of the chuck enters the centre hole of the saw cut. Fix the chuck in the wood by giving the end of the wood or the end of the chuck a smart blow with a hammer. Adjust the back poppet k {see Fig. 1), and then screw in the spindle I so that its centre n enters the hole at the other end of the wood, first putting a little grease, oil or black lead in the centre hole. Fig. 9. Fig. 10. Figs. 9 and 10. — Two Views of Prong Chuck It is advisable to screw up the spindle I fairly tightly at first; any binding resulting therefrom will disappear after a few revolutions. Now adjust the tool rest m (Fig. 1) until its top edge is below the centre of the work, and so that the wood when revolving is just clear of the front edge of the rest. Take the gouge and work the treadle to cause the top of the work to turn towards you at a faii'ly high speed. Rest the rounded side of the gouge on the top side of the rest m with the hands well down so that the cutting edge will be higher than the hands. It is essential to hold the gouge very firmly, the right hand grasping the handle with thumb uppermost and the left hand grasping the tool with the knuckles uppermost a few inches from the rest m. Now press the 223 Every Boy His Own Mechanic tool forwards towards the work until it begins to cut, and then move it along until a few inches are reduced to the same diameter. Then press the tool farther, and move it back again until the beginning of the cut is reached, and so on until the desired diameter is obtained, adjusting the height of the tool rest as required. It is always advisable to turn the larger diameters first before turning the smaller ones. In the present case the main portions of the handle will first be turned, then the ends reduced ; the one end a {see Fig. 11) nearest the fixed centre should be turned down to fit into a short Fig. 11. — Turning the Tool Handle length of brass tube to form a ferrule so as to prevent the handle splitting when the tool is driven into it. A pair of outside callipers (Fig. 12) will be required to gauge the diameter of the work, and since it will be neces- sary hereafter to have means for measuring internal diameters such as holes, hollows or insides of boxes, etc., it will be as well to get a pair of inside callipers also (see Fig. 13). To use callipers, first set them to the desired diameter by placing the end of one of the legs against the end of a rule, and extending them until the end of the other leg coincides with the required measurement on the rule. Always bring the work to rest in the lathe before attempting to calliper or gauge it. If the cut is not satisfactory or the wood is torn rather 2?i\ Turning Wood in the Lathe than cut the fault will be found to be : (1) Speed not high enough. (2) Tool not sharp enough. (3) Wrong position of the cutting edge. The third fault is the most common. The remedies for the first two faults are obvious, while the third can usually be put right by dropping the hands a little so as to raise the cutting edge of the tool ; but see that the tool rest is at the correct height. Fig. 12. — Outside Calipers Fig. 13. — Inside Calipers After the whole surface has been turned or "roughed out " with the gouge to the desired size, it will be found that the surface consists of a series of ridges instead of being smooth. To obtain a smooth surface, the chisel must be used. This tool, like all cutting tools, must be kept absolutely sharp, and a good oilstone is therefore a very necessary item. To use a chisel properly is very much more difficult than the use of the gouge. It must be so held in relation p 225 Every Boy His Own Mechanic to the work that only the middle part of the edge does the cutting. It must not be used, as is so often the case with amateurs, as a scraping tool. Fig. 14 shows the proper way of using the chisel, a being the cutting part of the edge, the highest point or edge a^ being above and out of contact with the work x, whilst the lower point a^ is below and also out of contact with the work. In such a position a smooth, even surface will be produced as the tool is moved along the rest m from right to left, but con- siderable practice will be required to prevent the edges a^ or a* digging into the work. An easier way of obtaining a smooth surface is to use an ordinary Fig. H.-Using Chkel In Wood Turning carpenter's chiscl sharpened to a truly square edge on one side only. The bevel of the chisel should be underneath and the top side of the chisel should be in line with the centre of the work. As a chisel so held scrapes rather than cuts, it will be necessary to sharpen it continually. When the surface has been gone over and reduced to the desired size with the chisel it should be perfectly smooth, but this is seldom obtained at a first attempt. To make it quite smooth, take a piece of fine glasspaper and press it lightly on the surface backwards and forwards whilst revolving the work at a high speed. To polish the work, press against it whilst it revolves in the lathe 226 Turning Wood in the Lathe a rag dipped in linseed oil or smeared with beeswax and turpentine. The end a^ (Fig. 11) of the handle must now be cut off. To cut off a piece of work in the lathe a parting Fig. 15.— Cutting-off Tool tool, illustrated by Fig. 15, is employed, and must be held at right angles to the axis of the work and advanced into the work in that position without moving it to the right or left. It is not advisable to cut right through with the parting tool owing to the liability of the work to break and perhaps be spoilt ; it is better to turn down as much as possible without breaking, remove the work from the lathe, and to cut off with a fine saw. In the present case it will not be necessary to use a parting tool, as the end to be cut off will already be turned down to a fine neck, which can be easily sawn through, and the saw marks removed by means of glasspaper. Having turned the handle satisfactorily it will be an easy matter to use the knowledge so gained in doing ... , Fig. 16.— Another Tool Handle more ambitious work. Fig. 16 shows a slightly different form of handle, Fig. 17 a bail or spindle, Fig. 18 a chair or stool leg, and Fig. 19 a drawer knob or handle, all of which can be turned after some practice. Screw Chuck. — It is not always convenient or even 227 Every Boy His Own Mechanic possible to turn some work between centres ; take, for instance, a powder box (shown in section in Fig. 20) or an egg-cup (see Fig. 21) or other articles requiring to be hollowed out. In such cases the block of wood must be held on to the mandrel by some other means than the prong chuck already described. Fig. 22 shows a screw chuck which will be found very useful ; this, as shown, comprises a shank a fitting into the end of the mandrel (or in some cases it may be pro- vided with a socket to screw on to the mandrel nose), a plate b and a tapered wood screw c projecting centrally Fig. 17.— Bail or Spindle d ^nOOdir:^^ Fig. 19. — Drawer Fig. 18. — Leg of Chair or Stool Knob or Handle from the face of the plate b. In use, a centre hole is first made in the wood, and then the wood is screwed on to the screw c until its back surface (which should be first planed true) butts against the plate b. The taper screw chuck can be employed only when the diameter of the work is fairly small and is not of great length ; if it is required to turn a disc or a wheel or a circular picture frame {see Figs. 23 and 24, which are a front view and side section respectively) it is better to screw the wood either directly on to the face plate o {see Fig. 1) (a slotted disc fixing on to the mandrel ; it is part of the furniture provided with most lathes, even of the simplest form) with wood screws passing through the slots from the back of the plate into 228 Turning Wood in the Lathe the wood held flat against the face or by screwing the wood from the front face on to a piece of wood pre- viously secured on the front surface of the face plate. Fig. 20.— Section through Powder Box Fig. 21.— Wooden Egg-cup When it is necessary to turn one part to fit within another, such as the lid to fit on the box (see Fig. 20), it is advisable to turn the hollow part of the joint first and then turn the outer part to fit within the hollow part, because it is easier to turn an outside part to an exact size than it is to turn an inner surface to a precise dimension. Woods for Turning. — As a general rule, hard and close-grained woods, such as box, rosewood, holly, lime, ebony, teak, beech, ash, apple and pear, are better suited for turning than the more open - grained hard woods, such as oak, walnut, elm and mahogany, or the common soft woods, such as pine, yellow pine, spruce, poplar and sycamore. Turning Tapered Work. — Occasion may arise when it may be necessary to turn a tapered pin or spindle, 229 Fig. 22. — Screw Chuck Every Boy His Own Mechanic the taper to be gradual and even from a larger end to a smaller one. This may, of course, be accomplished by carefully advancing the tool nearer the centre as it approaches the smaller end of the work, but such an operation requires much skill and practice to be per- formed successfully. A much easier way is to " set over " the tailstock, that is, to move it in such a way that the centre carried by it is not in line with the centre carried by the headstock. Figs. 23 and 24. — Elevation and Section of Wooden Wheel, Picture Frame, etc. Most lathes will allow of the tailstock being set over, in which case turning a gradually tapering article presents no more difficulty than turning an article with parallel sides. The amount of eccentricity given to the back centre (in other words, the distance which the back centre is put out of line with the front centre) governs the amount of taper produced. 230 HOW TO MOUNT PICTURES I WILL not trouble you with many particulars with regard to the mounting of pictures. Engravings and similar pictures of value are rarely mounted, but are inserted in the frame just as they are ; but presentation plates, cheap prints in general, and often water-colour drawings and the like, require to be mounted on stiff paper boards, which are obtainable in all the regular sizes, such as 24 in. by 19 in., 30 in. by 21 in. or 22 in., 33 in. by 26 in., and several larger sizes. The picture, etc., having been carefully trimmed up with sharp knife or scissors to lines previously drawn by means of T-square and pencil, is laid face downwards upon a piece of clean newspaper and brushed all over with flour paste, made by mixing a tablespoonful of flour with a cup of cold water, and boiling until the paste becomes more or less translucent ; or a starch paste, made in a similar way, may be used. After a few minutes' interval, brush on lightly a second coat of paste. What is wanted is not a thick coat of paste, as that would squeeze out and prove a nuisance, but a well-worked-in thin coat, the moisture in which will make every part of the paper amenable to pressure. See that your fingers are perfectly clean, lift up the 231 Every Boy His Own Mechanic pasted print, turn it over, and lower one edge of it into the position already marked with faint lines on the mount. Then let the rest of the print come into contact, cover the whole with a piece of perfectly clean paper, and rub with a clean handkerchief or duster from the centre so as to expel all air and make the print lie perfectly flat. If any paste oozes out at the edges of the print, wipe it off rapidly with a perfectly clean sponge or cloth and clean water. Cover the print with a fresh piece of paper (the old piece pro- bably has some paste on it which might spoil the picture), and place under a pile of books or in a press to dry. There is a trick of stretch- ing the print when laying it on a mount. I have fre- Sri::r« q^ently adopted it, PAtTL o«^ and find it to answer StCCOTINE- very well, but the Fig. 1.— Stretching Print on mount needs to be stout to Mount (also applicable to _ n i • Straining Drawing-paper on resist the pull of the print. °" ' With a brush or pad of clean cloth, rub some water over the back of the print, but leave perfectly dry a margin about 1 in. wide at all four edges {see Fig. 1). Allow two or three minutes for the moisture to expand the paper. Apply some really strong paste (seccotine or a similar cement is better) to the dry margin, and very carefully lay the print on its mount. Gently smooth out any wrinkles on the margin of the print, but do not touch the centre part, however hopeless at this stage the job may look. Put it away for a few hours to 232 r 1 I I WLT THIS CENTltE.- I PA.R.T WITH CLtAN ' I V/A>TiR. I I I 1 I How to Mount Pictures dry, at the end of which time it will be found that the paper has considerably contracted, and the print is now as taut as a drumhead,. As a matter of fact, the parchment heads Fig. 2.— Mount-cutter's Knife of certain instruments are stretched taut by a similar method. Mount Cutting. — Cut mounts of many different materials, sizes and shapes can be had from picture- framing shops. A touch of seccotine is the best means of securing prints to the backs of such mounts. Should you be sufficiently ambitious to attempt to cut out a sunk mount for yourself, you will need a very thinly ground penknife, and had better spend ten minutes in making it extremely keen on a knife-polishing board, wiping it on a duster when finished. The proper ^^^^^^^ ^^^^^ tool is the mount- cutter's knife shown in Fig. 2 ; the steel blade has a very keen edge, and slides in and out of a wooden handle, at one end of which is a brass ferrule which takes the clamping screw. For straight mounts, the knife is guided along in contact with a straightedge ; for curved mounts 233 1 jl [ ^ Fig. 3. — Diagrams showing how Bevel of Sunk Mount affects the Apparent Thickness Every Boy His Own Mechanic everything depends upon the worker's skill, and I do not advise you to try, as the result is not worth the expendi- ture of time and material in practising. According to the angle at which the knife is held the sinking is given an effect of thinness or thickness [see Fig. 3). Setting Out an Ellipse. — Oval mounts need to be set out with pencil before attempting to cut them ; in my opinion they are best avoided, but as I know many people like them, and as ellip- ses are often wanted in mechanical work, I will show the most prac- ticable method of setting them out ("oval" means really egg-shaped, whereas what are known as " oval " mounts are truly elliptical). Place the mount on a drawing board and draw a horizontal pencil line about midway between the top and bottom edges. Mark off on this two points a and b (Fig. 4) to represent the length of the oval (the "major axis" in geometry). Mark a centre point between a and B as at c, and with the T-square or set-square drop a line at right angles to the point d. Now c d will be exactly half the depth of the opening required (by the 234 Fig. 4. — Drawing an Ellipse with Piiss, Thread and Pencil How to Mount Pictures way, I advise you to cut the opening first on common white paper, and place it over the photograph or picture to see whether you have struck the right proportion). With compasses measure from c to b, and, without alter- ing them, with d as centre, make two marks on the major axis as shown, and drive in a pin or needle at each of the intersecting points. Pass over the pins a loop of thread, of such a length that when it is stretched downwards by means of a pencil the latter just touches D. There will now be a triangle of thread, and by using the pencil to keep the loop taut and at the same time moving it about round the pins it will be found to trace an ellipse, as shown. Probably many of you are quite familiar with the method, but I have often found that boys when attempting it do not know how to go to work when given definite lengths for the major and minor axes. On a large scale, the method can be used to set out garden beds, using posts instead of needles, string or rope instead of thread, and a dibber or poker instead of the pencil. The illustration (Fig. 4) shows a thread not looped but secured at its ends to the pins. Some experienced draughtsmen prefer this method. White and Gold Lines on Mounts. — Good effects are sometimes obtained by mounting prints and water-colours 235 Fig. 5. — Using a Draughts- man's Ruling Pen Every Boy His Own Mechanic on brown mounts, a simple line of white being run round on the mount half an inch or more from the picture. Such lines can be drawn with diluted Chinese white used in a draughtsman's ruling pen (Fig. 5), but the job needs to be done quickly, as the white soon clogs the pen and frequent cleaning out will be necessary. An ordinary writing-pen nib may also be used. For gold lines on picture mounts, rule the lines with gum water, allow to set, but not to dry, breathe on them, and at once dust over them some gold bronze powder ; a better and more permanent effect is obtained by dabbing gold leaf on the gum lines, in which case the gum needs to be strong and to have a little sugar dissolved in it. Edges of mounts can be gilt in the same way, or strips of gold paper may be gummed on. 236 SOME EASY THINGS TO MAKE IN WOOD A Lamp Bracket. — A simple but solid lamp-bracket is shown on the next page. It is made wholly of |-in. material, which, naturally, will be a trifle thinner than this when finished. There are four pieces. The long wall piece is 7 in. long and 2| in. wide ; it will require to be cut a little larger than the dimensions here given to allow of planing up. The top shelf is 3| in. square, and its shape is shown in detail in the plan (Fig. 3), while Figs. 1 and 2 are two elevations in which the shelf is shown simply in edge view. The lower shelf should be made originally as a part of the back piece so that it will be exactly the same width. It is 2 in. from back edge to front edge, but | in. of it is housed into the back piece, and its outer corners are rounded off {see Fig. 4). The bracket piece under the top shelf will be cut from a piece measuring 1| in. by 2| in., and the method of striking the curve to which it requires to be cut is given in Fig. 2, where d is the centre for the compasses. First plane up all the stuff and get it true and square. Dealing with the back piece first, Fig. 1 shows how the foot of it is struck to a curve, the centre for the compass being 1| in. up and 1\ in. from either side. The curve can be worked with a saw if the wood is left originally a trifle long, or perhaps it will be easier to execute it with 237 Every Boy His Own Mechanic a sharp chisel, but the square shoulders | m. from the bottom could be cut in with a fine saw. A groove should be cut for the bottom shelf exactly as shown, its depth being half the thickness of the material. Nothing need be said about the bottom shelf c — its shape is quite clear Figs. 1 and 2. — Front and Side Elevations of Lamp Bracket I I a^"-{--^ I 17 LJ.i ^U^ Fig. 3.— Plan of Top Shelf Fig. 4. — Section through Back piece, showing Plan of Under Shelf ^38 Some Easy Things to Make in Wood from what has been said already. The top piece is per- fectly square except for the hollowing out of the two front corners executed with saw or gouge. It is simply laid on the top of the back piece squarely, and nailed or screwed on. The bracket piece is cut to the curve shown, and should be screwed on, there being, say, one screw through the top and two inserted from the back. Folding Book Rack. — The book rack shown in Fig. 5 is a base with plain or bevelled edges and two hinged ends. If desired these ends can be permanently fixed upright by means of screws inserted from underneath. Fig. 5 is — 1' o Q Making Dovetail Joints in Wood means of an awl or the point of a knife. The template will last a lifetime. First we will cut the pin on the piece a (Fig. 1). The shoulder of the joint must be set out with a square or gauge on all four sides of the piece. Across the end grain of the stuff gauge a line at half the thickness, and square this line down on the edges to meet the shoulder lines already set out. Put the stuff in the vice, and saw down with the grain parallel with the face until you reach Fig. 6 Fig. 5. — Obtaining Dovetail Angle with Sliding Bevel Fig. 7 Figs. 6 and 7.— Metal Template before and after Bending the shoulder lines. You must next remove a half thick- ness of stuff, so on that face opposite to the one where the ^ dovetail is to be, cut in with a saw to half the thickness, so as to detach a piece of wood. Next with a saw cut in on the shoulder lines on the edges until you reach the slant Hnes that define the sides of the pin. Then put the work, slightly inclined, into the vice, and remove the waste chip by chip with the chisel, the handle being held in one hand, and the lower part of the blade between the thumb and first finger of the other. s 273 Every Boy His Own Mechanic For the setting out of the socket piece b (Fig. 1), either the bevel or the little template can be used, the lines being squared down on the two edges to meet a horizontal line at half the thickness, which will be obtained by means of the gauge. The waste will be removed by sawing down on the slanting lines and then with the chisel taking out the stuff chip by chip, as explained on page 273. A more accurate method of setting out the socket piece is to use the pin already worked as the template or pattern, laying it on the second piece of wood and marking the outline of the socket by means of Fig. 8.— Scribing Socket from Half- lap Dovetail Fig. 10.— Scribing Pin from Socket of Single Dovetail Fig, 9. — Single Dovetail Set Out, and the Socket Sawn and Worked awl or knife, taking care afterwards to saw down to these lines in the waste, the reason for which precaution I have already remarked on in an earlier chapter {see Fig. 8). 274 Making Dovetail Joints in Wood The form of single dovetail shown in Fig. 2 is excellent for framework. In this case it is better to cut the socket first and to mark out the pin from this. As before, you need to see that the shoulder line is squared on all four faces (Fig. 9), while the slant lines across the end must be set out by means of bevel or template ; lines connecting these slant lines to the shoulder lines on face and back of stuff are then drawn by means of square and pencil. Put the work vertically in a vice, saw down on the slant lines, and remove the waste with a chisel as usual. Place the socket piece on the other member of the joint to form a right angle, and with a slender awl scribe the shape of the pin on the work as shown in Fig. 10. Square the shoulder lines and also the lines across the end, then saw down outside the slant lines, and cut in from the side so as to detach the two small pieces. Often it is possible to save a great deal of time in cutting out a large dovetail socket by using a bow-saw, as in Fig. 11, cleaning out the socket by means of a chisel. The bottom of the socket is finished with the chisel held bevel outwards, the work being laid on the bench with the narrower part of the socket uppermost — a most important point. 275 Fig. 11.— Sawing Out Waste of Large Single Dovetail Every Boy His Own Mechanic The Box Dovetail. — There is a great variety of dovetailed joints, but I propose to explain only one more, and that is the box or com- mon dovetail (Fig. 12). For a start, do not attempt to make a very fine joint, but work in common wood, and make the angle of the dove- tail slight. As in all joint making, the setting out is of the greatest importance, and this setting out can only be properly done after the wood has been carefully planed up smooth and parallel, and the edges have been shot true. I have already explained what " shooting " is. The work is held in a shooting board over which its edge very slightly projects, and a keen plane is then " shot " along to take off a very fine shaving or two from the end grain. Shoulder lines must now be squared or gauged round (see Fig. 13) on both pieces, and, as in all joints of this simple kind, these lines will be distant from the ends of the stuff by an amount exactly equal to the thickness of the stuff. In the first place, it is easy to get confused as to which 276 i^ Fig. 12. — Common or Box Dovetail Joint Fig, 13. — Gauging Shoulder Line for Dovetail Joint Making Dovetail Joints in Wood Fig. 14. — Spacing Dovetail Pins with Dividers piece carries the pins and which piece contains the sockets, because, as a matter of fact, there are pins and sockets on each of them ; but in the joint shown by Fig. 15 the part that carries the four thin projections has the " pins " whilst in the other are two com- plete sockets and two half - sockets. Woodworkers do not agree among them- selves as to whether the pins or the sockets should be cut first, but I am going to describe the " pin first " method, and I think you will find it quite satisfactory. We will have chosen two pieces of board in which two complete pins and two end pins can be cut, as in the illus- tration (Fig. 15). The shoulder lines have been squared round. At the extreme ends mark off on the face from each edge half the thickness of the thinnest part of a pin. This " thinnest part" is shown on the edge of the socket piece, and its dimension varies with the thickness of the stuff that is being joined up. For wood up to f in. thick, the thinnest part of the pins may be I in. thick, but don't aim at too fine work at the start. With dividers or compasses {see Fig. 14) 277 Fig. 15. — Common or Box Dovetail Joint Every Boy His Own Mechanic divide the space between the two points already marked on the shoulder line into three, and set off on each side of these marks half the thickness of the pin. Set off that distance also inside the two end marks already made. Next, with a small try- square and an awl, draw lines from the shoulder line to the end of the work to indicate the sides of the pins {see Fig. 16). The slant of the dove- tails will now need to be in- dicated on the end grain of the piece, for which purpose you must fix the wood vertically in a vice, and by means of a bevel or template {see Figs. 17 and 18) mark the ends of the pins across the end grain, continuing the work by means of the square on the back of the work so as to draw the sides Fig. ^6. — Squaring Down Dovetail Pins Fig. 17. — Marking Ends of Dovetail Pins from Sliding Bevel Fig. 18.— Marking Ends of Dovetail Pins from Template of the pins as far as the shoulder line. The little template illustrated can easily be made by the boy mechanic in wood, or, as already explained, in metal, or it can be bought ready made. 278 Making Dovetail Joints in Wood Keeping the wood fixed vertically in the bench vice, cut down with a fine saw on the slant lines which cross the end grain, but see that the saw cuts keep accurately to the parallel lines that have been squared down from the end to the shoulder lines. A chisel is used for cutting out the waste, but, by the way, first make sure which is the waste, and to prevent mistakes it is better after setting out to mark with a pencil cross any stuff that is to be removed, as otherwise an accident or mistake is the easiest Fig. 19. — Scribing Dovetail Sockets from Pins Fig. 20. — Squaring Ends of Dovetail Sockets thing possible. Your best plan will be to use a fine carving chisel, particularly if the work is rather small. Clean out the recesses between the pins, and do everything you can to produce sharp, true edges, and a perfectly flat bottom to each of the recesses. Of course, each recess is really a socket, but if I label them "sockets," you may easily become confused between the pin piece and the socket piece. This box dovetail is really, as by this time you will have discovered for yourself, a number of single dovetails 279 Every Boy His Own Mechanic cut side by side in the same piece of wood, and you will therefore be prepared to understand that the socket piece is set out by " scribing " — that is, the pin piece is laid on the other member of the joint (on which the shoulder lines have already been squared), and a slender pointed awl is used as in Fig. 19, to " scribe " the shapes of the sockets from the pins. As all you have so far marked on the socket piece is the shoulder line and the slant lines on one face, you will need to use a square (Fig. 20), and continue the socket lines across the edge of the stuff. The sockets are cut out in exactly the same way as the pins were formed, having previously taken the trouble to mark with a cross the parts that are to be removed. 280 TURNING METAL IN THE LATHE By a. Millward With the lathe as described in the chapter on wood turning it is quite possible to do a limited amount of metal turning of a light and simple character. For in- stance, it may be desired to turn a small knob or handle in brass, or turn a small rod or spindle, or do a number of small jobs as necessity arises ; and these are quite pos- sible in the lathe shown on p. 220. Metal - turning Tools.— These have quite different cutting edges from those of wood-turning tools, due to Fig. 1. — Metal-turning Graver the difference in hardness and character of the material to be turned. Since the lathe is only adapted for very light metal turning it will be better to confine the attempts to turning in brass, and for this purpose a single tool, a "graver," will probably be all that is required. This {see Fig. 1) comprises a bar of square steel sharpened at an angle so as to produce a diamond-shaped point ; the face of the tool must be kept perfectly fiat, and the tool must be kept well sharpened by grinding the flat face only. 281 Every Boy His Own Mechanic Rest and Chucks. — A metal-turning rest is usually flatter on its face and of a greater width but of a less length than one used for wood turning so as to provide a greater width of bearing surface for the tool. A " chuck " of some kind for holding the metal is a necessity for any work that cannot be held and turned between centres. A " self-centring chuck " will save much time if round or circular work is to be turned. Such a chuck comprises three radially arranged jaws, which can be moved equally towards or away from the centre, and between which the work is gripped. For holding irregular work a chuck having independently movable jaws will be required. A Simple Metai-turning Job. — In order to turn a bar or spindle between centres proceed as follows : — Having obtained a bar of a suitable length, first square or file the ends so that they are at a right angle to its length. Now find the centre, that is the axial centre, of the bar by marking intersecting lines on its ends. A convenient way of doing this is to mark two lines at an angle to each other by means of a centre square, a little tool somewhat resembling a T-square but having, in some types, two pins in the head of the squares ; the edge of its blade intersects at right angles a line connecting the two pins. Another method is to set a pair of dividers to approximately half the diameter and to scribe a series of lines by resting one leg of the dividers on the edge or circumference whilst the other one is used for marking the end face ; finally the centre between the marks must be judged. Mark the centres when found with a centre punch, and then, on each end, drill a small hole 282 Turning Metal in the Lathe about I in. deep. Now take the centre punch, which should be sharpened to the same angle as the lathe centres (usually 60 deg.), put the point in the hole and hit it smartly until a coned-shaped hole results, which forms a bearing for the lathe centres when the bar is placed between them. It is now necessary to pro- vide means to cause the bar to rotate with the rotating man- drel of the fixed headstock. For this purpose a "carrier" is used. A simple form of carrier is shown in Fig. 2; the rod a is inserted in the ^ hole b, and the carrier gripped to the rod by screwing up the screw c. The carrier is so fixed on the rod that the end d comes into contact with a pin or driver secured on the face-plate. The graver is now held firmly on the rest, which is so adjusted in height that the point of the tool can be held so that it is in line with the axial centre of the Avork ; the position will be quickly found by experiment, as the tool will not cut properly unless the correct position is found. The tool must only be moved towards the work very gradually so as to remove quite a small amount of metal at a time. When the desired diameter is reached 283 Fig. 2. - Metal-turner's Lathe Dog or Carrier Every Boy His Own Mechanic the tool is turned over so as to present one of the sides of the diamond-shaped face to the work, which will remove the irregularities produced by the point of the tool. With a little practice a perfectly bright and smooth surface can be obtained which will not require any further finish- ing. By altering the angle or position of the " graver " tool it will be found possible to produce rounded surfaces, V-shaped grooves, square recesses or shoulders, but it will not be possible to produce rounded hollows with it, for which purpose a rounded hollow-nose tool will be necessary. 9B4 FRETWORK IN METAL AND IVORY Equipment. — Saw-piercing in metal is a higher stage of the fret-cutter's art. It requires special saw-blades having very much finer teeth — so fine that the unaided eye can scarcely see them. A suitable grade is No. 00, and only the highest quality with rounded-backs should be bought. The woodworker's fretsaw frame can be used if desired, but a smaller frame is more suitable. The type shown in Fig. 1 has the advan- tage that the handle part slides along the back when the thumbscrew is loosened, thus allowing of broken pieces of saw - blade being accommodated. Fig. 2 compares fretsaw blades for wood and metal. Ordinary paste does not adhere very well to metal, and it is better to use a mixture of starch, gum arable, and sugar. The gum arable can be bought at any oilshop. One ounce of it placed in a piece of muslin and soaked for a few hours in water and then turned out into a jam-jar 285 Fig.l.- Metal Fretsaw or Piercing Saw Fig. 2. — Metal and Wood Fretsaw Blades Every Boy His Own Mechanic containing 1 oz. of starch and 4 oz. of sugar with about I pint of water will make a good paste for the purpose, the mixture being boiled until it thickens. Applying the Design. — Let us take a useful little pattern like Fig. 3, a design for a large brooch. Make a tracing of the design on thin paper, and, using only just paste enough, stick it down on the metal. (To get a pair of patterns when the design is reversible, make two tracings on very thin translucent paper, and in pasting them down see that one of them is reversed so that its face is in contact with the metal.) Allow to dry thoroughly before proceeding further. When the fretting is com- I>1 pleted, the remains of the paper will need to be soaked off in hot water. Professionals frequently adopt a different method of transferring the design. They use carbon paper and a Fig. 3. -Design for Large Brocch ^ard point for transferring it or Waistbelt Clasp ^ ° to the metal and then, while the lines are fresh, go over them with a steel point, which gives them an indelible nature. Metal that has been smeared with gamboge (a lump can be bought at a chemist's for a trifle, and most colour-boxes include it) and allowed to dry can be drawn on with an ordinary pencil. The "pouncing" method is useful in transferring all kinds of designs for all sorts of purposes. The pattern or a tracing of it is converted into a stencil by pricking 286 Fretwork in Metal and Ivory over its lines with a fine piercer, awl or needle ; the coarser the pattern, the wider may the holes be spaced. The stencil is laid down on the metal and rubbed over with a little muslin bag containing fine chalk, the pattern then appearing in dotted lines on the metal, and being easily made permanent by going over them with a fine pen or hair pencil and brunswick black thinned with turpentine, or by scratching over them with a steel point. The stencU can be used scores of times, and the method could be employed for wood fretwork, using, instead of the black, a very dilute mixture of Chinese white and water, and applying it in such thin lines that the saw would utterly obHterate them. Using the Saw on Meta!. — The saw should be worked much more slowly and deliberately on metal than on wood, very little pressure should be apphed, and the point of cutting should be kept supplied with oil or with turpentine, which, together with an occasional rub of the saw on a piece of beeswax, will make a big differ- ence to the ease and speed of working. The blade soon gets hot with the friction, and must be given a few moments to cool before proceeding. As before, holes must be drilled to take the blade, for which purpose the Archimedean drill stock AviU come in handy again, but the boring-bit used on wood will not be suitable, and in its place you must get a tiny twist-drill, and keep it lubri- cated with turpentine, bearing in mind that it is not strong enough to stand much pressure. An alternative method is to prick through with a fine piercer or awl, first placing the metal on a block of hard wood. Beautiful fretwork can be done in copper, brass, 287 Every Boy His Own Mechanic aluminium, ivory, ebonite, and, of course, gold and silver ; when working in the precious metals there should be a bag of leather or waterproof material underneath the bench to catch the waste, as this has market value. Silver works out fairly expensively, but for occasional articles, such as pendants, ladies' ornaments, etc., it may be used of No. 23 gauge metal (standard wire gauge), which is -024 in. thick, and equivalent to about 9 sq. in. to the ounce — enough for, say, two club badges, or for five hatpin heads or charms. The saw cannot do the whole of the work, and you will soon find that much of the delicate detail must be executed with tiny files, of which two or three selected shapes, including a needle file, should be bought. Files, also, must be used for correcting outlines. A triangular file is best for the sharp angles. Finishing. — The cutting having been completed, the paper pattern (if used) must be removed with hot water, and the metal laid upon a block of wood or lead and worked over with fine pumice powder and water rubbed vigorously with a large smooth cork. This will remove any swarf at the cut edges and prepare the piece for polishing, which is a matter of time and patience, and is done with a soft leather and tripoli powder and oil, finishing in the same way with jewellers' rouge appHed dry. 288 BUILDING A DOG KENNEL In this chapter I am giving you drawings for a big kennel. Some of you may think it is far too large, inasmuch as it is 4 ft. long by 3 ft. wide, but I am taking a rather big construction because, as a matter of fact, the actua making is easier in the case of a large kennel than with a small one, and there is no reason whatever why you should not build, from the instructions and drawings here given, a much smaller house should you so wish. For example, if you reduce length and breadth to 2 ft. Fig. 1. — Dog Kennel Solidly Built in Sections T 289 Every Boy His Own Mechanic Fig. 2. — Front Elevation of Kennel and packed flat, while the construc- tion is very solid and good enough for a lifetime's use. You must study the drawings before you cut a single piece of timber, so as to realise fully what you propose to do. There are seven main pieces in the construction : the floor, four sides, and two roof pieceSj^and and 1 ft. 6 in. respec- tively, you get a very nice size kennel for a small terrier, and the drawings will still answer exactly as before, except that the bearers and ledges need not be so thick as shown in the illustrations. There are some excellent points about the kennel here shown, not the least of which is that it can be readily taken to pieces Fig. 3. — Longitudinal Section through Kennel 290 Building a Dog Kennel each of these is built up as a separate unit. You will notice in the illustrations that a number of bolts and nuts are shown. I advocate these if there is any chance that the kennel may not be required for some time, or if it is to be made in one place and transported to another ; but there is not the slightest reason why you should not use 2|-in. or 3-in. brads or nails (to be clenched over) or 2|-in. screws if you so prefer. i^)j M)i>}n>>jj,AM ^^>^^ff}}JWPJ ! G THZn^ ^jSBSm Fig. 4. — End Elevation of Kennel Fig. 5. — Horizontal Section through Kennel You will realise that the principle of construction is first of all to build up the seven main pieces accurately to size, and then bolt or nail them together. This is a much better plan than building up the kennel as a whole, board by board, and it is a method which you will find always answers best in any work of this kind — poultry houses, beehives, summerhouses, and so on. All portable constructions are bcs>t built in sections, as here shown. 291 Every Boy His Own Mechanic You can make a start with the four sides, or rather with the front, end, and two sides. All the boards consist of grooved and tongued stuff 6 in. wide and preferably 1 in. thick, but slightly thinner if you like ; | in. stuff would do for a small kennel. See that the boarding is planed up and fits well together before it leaves the timber yard (if you are buying it locally). You can take all the dimensions from the drawings, which, except the general view, Fig. 1, are to a scale of I in. = 1 ft. Fig. 2 is the front ele- vation, Fig. 8 the vertical section length- ways of the kennel. Fig. 4 the end eleva- tion, and Fig. 5 a plan or section through the body of the kennel. As here shown, the sides are 3 ft. 1^ in. high, but, of course, you are at liberty to vary this by an inch or two as you think proper. Eight widths will be required, and they will be nailed top and bottom to two bearers or ledges,. A and b; the top one a is 2 in. deep and 1| in. thick, and the bottom one b. 3 in. deep and 1| in. thick. These bearers or ledges will come flush with the top and bottom edges of the boards. At the ends you will nail fillets or angle pieces g, which need to be about 1| in. square, and the construction when this has been done will resemble Fig. 6, which shows the inside view of one of the sides. It will be necessary to saw off the extreme ends of 292 Fig. 6. — Internal View of Side of Kennel Building a Dog Kennel the fillets or angle pieces to accommodate the top and bottom ledges, as shown in Fig. 6. Both of the sides of the kennel will be the same. Now for the front and end. All the materials will be of the same thicknesses, etc., as for the sides, and the pieces will be built up by means of two bearers or ledges as before, as shown at c and D. The front and end are 3 ft. 1| in. high to the top of the sides and about 4 ft. 8 in. high to the apex of the angle or gable. Fig. 7 is the inside view of the front or end, showing the positions of the bearers, and it will be noted that these are cut away at the ends to allow for the ledges a on the sides when the four main pieces come together. The entrance hole in the front can now be cut. In the illustrations it is assumed to be about 1 ft. 9 in. wide, and about 2 ft. 8 in. high from the ground level, but this will, of course, depend upon the size of the dog, and whether you are working to the dimensions here given or to a much smaller scale. Set out the opening centrally with square, rule, compass, and pencil. Saw down with a hand saw as far as you can, but don't saw through the bearer d (Fig. 2), and finish with a turn or compass saw. Smooth the edges with glasspaper held on a block of wood, using, if possible, a curved block for the glasspapering at the head of the opening. It would strengthen the front if an extra fillet were nailed across (on the inside) under c (Fig. 2), and just over the opening, before cutting. We can now consider the floor of the kennel. As drawn, it is about 2 ft. 10 in. wide with an extreme length of 4 ft. It will be built up of about the same sort of 293 Every Boy His Own Mechanic material as was used for the sides, and nailed to two ledges as shown in section at f in Fig. 3, and also in the general view of the floor shown in Fig. 8. In Figs. 5 and 8, you will note that square notches will have to be made to clear the fillets or angle pieces, and, in addition, the front end of the floor is cut away at the sides so that the centre part projects a trifle past the opening. We have now to make the two parts of the roof. They will each consist of five widths of 6 in. wide material, of the same thickness as used elsewhere ; but one part of the roof will be narrower than the other by an amount equal to the thickness of the stuff used. If you study the front elevation (Fig. 2) you will easily see why. One part of the roof overlaps the other, and if they were of exactly the same width, the eaves at one side would be lower than on the other ; so if you are using | in. material, saw off a strip I in. wide, and you can probably do this more easily from the completed roof part. The bearers or ledges can be of the same material as the bottom ledges of the sides, that is, 3 in. by 1| in., and it is better to have three bearers for each roof part. You will, of course, note that the roof boarding is longer than the side of the kennel. A length of about 4 ft. 8 in. will give an overhang at each end of about 4 in., and this is advisable inasmuch as it helps to throw off the rain, keeps the dog more comfort- able, and preserves the kennel from decay. You need to be very careful in deciding the positions of the end roof bearers, as these must, of course, just clear the inner surfaces of the front and end of the kennel. Study Fig. 3, and this point will be obvious. We have now the seven main pieces, and before we do 294 Building a Dog Kennel anything more we might as well give them all, except the floor, a couple of coats of paint or good outside varnish, but do not paint the inside. A coat of brown or green stain before applying the varnish is not a bad idea. Let us set about assembling the kennel. We need a good flat, clean floor, or a flat bench top or table top upon which to work. Prop up one of the sides, m. "^^ Fig. 7. — Internal View of End or Back of Kennel Fig. 8. — Underneath View of Floor of Kennel and put the end in position against it. Having settled whether you are going to use bolts or screws, the latter being much the easier, it will be necessary in the case of bolts to bore holes from the end right through the angle piece, as fully explained in the detail sectional view (Fig. 9), which shows a section taken on the line h in Fig. 2 ; on the right is one of the sides to which g is nailed, and at the bottom is either the front or the end, to which g is bolted. One little 295 Every Boy His Own Mechanic point : You will notice that in this section the extreme corner of the angle piece has been trimmed off, with the object of not leaving any hard corhers for our friend the dog to knock himself against. Having secured the end, place the second side in position and proceed as before, taking great care that all the joints are square, and that there is no tendency for the rectangular construction to go out of shape as indicated by the dotted lines in Fig. 10. Fig. 9.— Details of Corner Joint of Kennel, showing Bolt and Nut Fig. 10. — Diagram showing Tendency for a Square Con- struction to go out of shape Now let us put the floor in. It will easily go into the three-sided box already formed if it is slanted a trifle. There is no real need to nail it down to the bearers, but you can please yourself. The front can now be added, and all will be ready to receive the roof. Get someone to help you to hold the two parts of the roof in something like their proper positions. You will find that some little adjustment with the plane will probably be necessary on the top edges of the sides, so that the roof boards " sit " well in place. The roof bearers are secured to the front and ends with bolts or screws, exactly as before. You will need 296 Building a Dog Kennel altogether eight bolts at each end of the kennel or a dozen screws. All the woodwork is now completed, but the construc- tion would not be watertight if left in its present state, and it is advisable to get some good-quality tarred felt with which to finish the roof, allowing the felt to project all round for about f in. A big kennel like this will of, course, be kept in a yard or garden, and so must be very well protected with paint or varnish against the weather. 297 LAYING THE RAILS FOR A MODEL RAILWAY By Henry Greenly The author's practical experience in this direction dates from the time when an ingenious and skilful friend made him a wooden model locomotive which had flanged wheels for running in the orthodox ■flange- ^1 N?0 M rl ~n _2. 64 read M IN? I ,iX" I 32. t' V-'i'--- -X N?2 3 » 64 Jl 2- 1^ 7. . 60- 3L Fig. 1. — Standard Gauges and Wheel Dimensions (Indoor Model Railways) manner on rails. At the outset the locomotive ran by force of gravity, but later it was improved by the addition of an "elastic" drive such as that now com- monly adopted for model aeroplanes. Clockwork motors and electric mechanisms had yet to make their advent for model locomotive work. The rails were hard wood strips of about | in. by I in. rectangular section glued and pinned down to a baseboard. The points were fashioned with a pen- knife, and were pivoted at 298 Laying Rails for a Model Railway the heel with a fine cabinet-maker's brad. This crudt affair, however, was sufficient to make clear the importance of accuracy in the matter of rail gauge and wheel widths. The " between-tyre dimension" is of the utmost import- ance in any railway, real or model. The London, Brighton and South Coast Railway suffered a bad accident at Stoat's Nest, due to the wheels of a carriage spreading out. Miniature " Stoat's Nests' " will happen continually on a model railway unless the work in these particulars is done Math a reasonable degree of accuracy. POl r- "1?" r?i rn. 1^ 90° Rvot Poinl- Fig. 11 Figs. 10 and 11, — Setting out Curves and Points with Trammels over a rail, and while the rail is broken the guiding effect of the flange is preserved by the system of wing and check rails, clearly illustrated in Fig. 2 Figs. 7 and 8 show the necessity of properly fitting up the wins and check rails. In the first sketch it is evident that a wheel will just as easily travel along the line of track if the check rail is either absent or is laid down 303 Every Boy His Own Mechanic with too great a space between it and the stock rail oppo- site the frog Where the check rail and wheels are correctly proportioned and properly fitted, the check rail acting on the opposite wheel to that traversing the frog retains the latter wheel in the straight and correct path. In all the small gauges the distance between the main and the check and wing rails is settled by the all-important " be- tween tyre dimensions," as shown in Fig. 9. The distance over check and wing rails, c w, should be y^th of an in, less in all the three small gauges (Nos. 0, 1 and 2) than the " between-tyre " dimensions given on the diagrams in Lorqc radius u-fiecfi 1 — z:r-=r. ^ \ AS SET OUT \ ddiAOii of Fig. 12.— Setting out Rails from Straight to Curve Fig. 13.— Sketch of " Rail- gauge " for Model Railway Work Fig. 1 (1 in., 1|| in., and Iff in. each gauge respec- tively). The space s (Fig. 2) is therefore half the difference between the dimension c w and the gauge g. In setting out ciu'ves and points the use of the " trammel " is strongly recommended. A very simple instrument of this kind is shown in Fig. 10. The centre point may be a stout needle or other stiff steel pivot, and to allow for scribing out the four lines (two for the rails and two for the edges of the sleepers) the pivot end of the wooden lath forming the trammel may be provided with 304 C/2 < I— I < W Q O » IHT-'I IT.] ■*'■ ,1!F^ Laying Rails for a Model Railway four holes for the pivot pin, each hole corresponding to the radius to be drawn. In setting out points (Fig. 11) the pivot point at which the trammel swings should be at exactly 90 deg. to the toe of the points (that is, the toe of the switch rail). In the case of ordinary curves which enter straight portions the best scheme is to provide a transitional entrance to the curve. In this case the curve is set out with the trammels as shown in Fig. 12, not exactly at a tangent, -Clir^-^^rr-— and the junction ^ - • - — -^ - between the curve made with a larger radius curve which can best be judged by eye. A " rail-gauge " made as shown in Fig. 13 is a simple ^:=::::OsC;;^--„^ z^'- device for setting ^^ ''^^^^ ''^jC:;: the rails true to fc gauge. It may be . „„ X Fig. 14.— How to Lay Frogs : A, Wmg made out of sheet rail space inaccurate ; B, Rails not in , -, , , , . continuous line ; C, Correct Spaces metal, tne strips ^g^^ l^ajl Ung continuous {see dotted being driven into ^*°® ^ ^^ saw cuts in a block of wood, or soldered to a metal base plate. In laying plain rails one rail should be put down first, tuned up by eye, and then the adjacent rails laid to suit, using the " rail gauge " instrument already described. Much -)f the final accuracy of the track is obtainable by sighting along the rail. Surface "wind" or "twist" u 305 Every Boy His Own Mechanic may also be observed by looking across from rail to rail with the eye on a level with the top face of the rail. When laying down points the lining up of the frogs is an important feature. The diagrams a and b (Fig. 14) are examples of " how not to do it." The inner edges of the running rails should line up accurately so that by a straightedge, or by the eye, it can be observed that the line of the inner edge, against which the flange runs, is continuous, just as though there were no frog there at all. This is shown at c (Fig. 14). Very much more could be said on this subject, but the variety of materials available is large and the minor features of each create special difficulties and conditions. The broad principle has, however, been covered, and is unalterable whatever kind of track material is used. 306 BUILDING A 10-FT. FLAT-BOTTOMED ROWING BOAT There are boats and boats, and most of them are beyond the capabilities of the young woodworker. I know, however, what a fascination the building of a knockabout boat has for boys young and old, and I therefore feel obliged to include a chapter giving drawings and instruc- tion on making a boat of a type within the scope of any- body at all handy with woodworking tools. The details of the design here presented are due to Mr. D. Kidd. Fig. 1 is the sheer draught or elevation of the boat, Fig. 2 is the half-breadth plan, while Fig. 3 is a section " amidships," that is, it is a section right across the centre of the boat. This is an excellent knockabout boat for lakes and rather sluggish rivers, being of comparatively light weight, very stable, and, owing to its design, not dragging water. It tows easily, can carry a big load, and does not require a professional boat-builder to construct it ; but like all flat-bottomed boats it is apt to pound in choppy water. It must be realised that this is a small boat — 10 ft. by about 4 ft. — and that any load it carries needs to be distributed properly. One person alone would occupy the central seat. Two people would have an end seat each ; 307 Building a Rowing Boat three would be distributed over the three seats, while, when there are four people, two would be on the centre seat and one at each end, one of the latter doing the rowing. Keeping to this rule will mean an even keel. You may care to know that the design has been adapted from that of the American fisherman's dory, the system of construction being practically identical. Briefly, the side planks are secured to a stem or stempost at each end, the inner upright tim- bers added, and the bottom then put on. The first thing to do is to prepare the " moulds." As long as they are strong and of the right shape and dimensions it matters not how they are made up. Two " quarter moulds," as Fig. 4, and one " amidship mould," as Fig. 5, will be required ; each of these is 18 in. high, and the former is 38 J in. wide at the top, tapering to 30 in. at the bottom, while the latter is 47 in. and 38| in. respectively. As illustrated, they are L. m CO .2* M •a 'a < I b Every Boy His Own Mechanic Fig. 4. -30 i -Quarter Mould built up of thick rough stuff 6 in. wide, well nailed at the joints, so that any " giving " at those parts is im- possible. A notch 1 in. by f in. is cut out at each bottom corner {see dotted lines). The stem or stempost at each end of the boat is the only detail that will tax the skill of the woodworker. You know that the stem is the upright or nearly upright piece at the sharp end -* of a boat, into which the planks are secured, and as, in this case, both of the ends are sharp, two such pieces will be required. They are about 22 in. long, and after the bottom planking is on they will need to be sawn exactly to size. The section through the stem or stempost is as shown in Fig. 6, which is very fully dimensioned. Probably you can get a joiner to supply you with a piece of oak, mahogany or other hard wood (softer stuff is useless) cut to the section shown, as it will be a rather awkward job to produce such a section at home ; but if there is no alternative I suggest that the best method of going to work is to get a piece of stuff 3 in. square and 22 in. long, and make in it a series of cuts with a tenon saw or dovetail saw, as indicated by the dotted lines in Fig. 7. This will have the effect of pro- 310 k 28%"- Fig. 5. — Amidship Mould Fig. 6. — Section through Stempiece or Stempost and Sides Building a Rowing Boat ducing a piece of the section shown in the hatched Hnes. and you will then need to divide this into two with a hand saw on the dash-and-dot line shown. Afterwards clean up with glasspaper. Now, I don't recom- mend this job. It requires a great deal of care, pa- tience and skill, and I think that if you can get the stuff cut for you so much the better. The side plank- ing is only | in. thick, and should be of good qual- ity. This thin stuff will readily bend to the shape required. Four planks will be re- quired, 8^ in., say 9 in., wide, two for each side, the upper one be- ing 11 ft. 8 J in. long, and the lower one 10 ft. 6| in. long. They should be placed together as in Fig. 8, and the centre line struck as indicated at a b. Then by setting out the dimensions shown on the diagram and drawing a slanting 3" Fi^. 7. — Suggested Method of Shaping the Stempost Every Boy His Own Mechanic line at each end right across the two boards the rake for the ends of the planks will be obtained, and the planks can then be cut on those Hnes. Both sides of the boat are the same, and it will be noticed that although in Fig. 1 a curve is shown, this curve is obtained naturally as a result of the design and system of building and does not need to be imparted to the planks by sawing to a curved line. Indeed, it is of the utmost importance that the f-f/dl--"^ ^