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 Notes on a Recent Study 
 
 OF THE . 
 
 Atlantic City Steel Paint Tests 
 
 SCIENTIFIC SECTION 
 
 HENRY A. GARDNER, Director 
 
 Educational Bureau 
 
 Paint M’f’rs Association of the United States 
 Philadelphia, Pa. 
 
 
 
 
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BULLETIN 32 
 
 Notes on a Recent Study 
 
 OF THE 
 
 Atlantic City Steel Paint Tests 
 
 SCIENTIFIC SECTION 
 
 HENRY A. GARDNER, Director 
 
 Educational Bureau 
 
 Paint M’f’rs Association of the United States 
 Philadelphia, Pa. 
 
Distributed by 
 G. B. HECKEL, Secretary 
 636 Bourse Bldg.. Philadelphia, Pa. 
 
 Copyright. 1912, by 
 H. A. GARDNER 
 
 THE GETTY RESfiAftCti 
 INSTITUTE LIBRMiy 
 
NOTES ON A RECENT STUDY 
 OF THE ATLANTIC CITY STEEL PAINT TESTS 
 
 By Henry A. Gardner, 
 
 Assistant Director, Institute of Industrial Research, Washington, D. C. 
 
 A recent inspection of the painted steel test 
 panels* erected by the Paint Manufacturers’ As¬ 
 sociation at Atlantic City during October, 1908 r 
 lias disclosed some startling changes in the 
 weathering of the various paints as compared 
 to their condition a year ago. These tests, which 
 include a great number of oil paints, are af¬ 
 fording most important information as to the 
 comparative value of various pigments, when 
 ground in linseed oil, as protective coatings for 
 ferrous metals. Several of the paints have given 
 excellent results, while others have completely 
 failed to serve their intended purpose. The 
 original contention upon which the tests were 
 based, that pigments of the rust inhibitive and 
 inert types, such as the slightly soluble chromates, 
 the basic compounds, and the metallic oxides, 
 would prove superior to those pigments of the 
 tentatively termed rust stimulative class, which 
 induce electrolysis either through the effect of 
 
 * Bulletin 27. Paint Mfrs. Asso. of tlie U. S. “Corrosion of Iron and 
 Steel.” Cuslnnan and Gardner: McGraw-IIill Book Co., X. Y. 
 
contained acid impurities or through their electro¬ 
 negative nature, has been fully justified. 
 
 While some single-pigment paints have failed in 
 certain respects, it is by no means certain that 
 these paints would act in the same way under con¬ 
 ditions of actual practice where they would be used 
 in combination with other pigments which might 
 tend to overcome their inherent defects. This 
 statement would apply especially to pigments of 
 the inert class, such, for instance, as barytes 
 or whiting. These pigments are never used 
 alone in paints. They are always combined 
 with some of the more opaque pigments in order 
 that their defects may be corrected, sometimes 
 lending in turn a strengthening effect to the pig¬ 
 ments with which they are combined. This point 
 is well illustrated in tests Nos. 19 and 21, in which 
 the pigment Barytes seems to have had the effect 
 of prolonging the life of the black carbon pig¬ 
 ments with which it was combined. 
 
 Panel No. 1, painted with Old Dutch Process 
 White Lead (Basic Carbonate-White Lead), and 
 Panel No. 2, painted with Quick Process White 
 Lead (Basic Carbonate-White Lead), are both in 
 very poor condition, their surfaces being covered 
 with rust streaks which appear wherever brush 
 marks were shown at the initial painting. Early 
 in the test these panels developed considerable 
 chalking, which was progressively washed off 
 to such an extent that in the summer of 1911 
 
 4 
 
r 
 
 a very tliin coating was left. This coating dur¬ 
 ing the past year has failed in a great many places, 
 scaling and marked signs of disintegration having- 
 appeared. 
 
 Panel No. 3, painted with Zinc Oxide, indicated 
 at the beginning of the test that the paint used was 
 too stiff and thus lacking in elasticity; Zinc Oxide 
 being a pigment which demands a considerable 
 quantity of oil. The rust lines on the paint, where 
 the brush marks were left, are heavy. What re¬ 
 mains of the paint, however, is very hard, and be¬ 
 neath the surface the steel is clean, indicating that 
 the pigment itself is of an inliibitive nature. 
 
 Panel No. 4, painted with Basic Sulphate-White 
 Lead, and Panel No. 5, painted with Sublimed 
 Blue Lead, are both in excellent condition. Al¬ 
 though considerable chalking was shown on each 
 of these panels, the paint films are intact and of a 
 tough, elastic nature, presenting to the touch a 
 velvety feeling. The Sublimed Blue Lead was 
 somewhat superior to the Basic Sulphate-White 
 Lead, although the latter showed better color 
 maintenance. 
 
 Panel No. 6, painted with Litliopone, indicated 
 at the beginning of the test that this pigment when 
 used alone was unfit for the protection of iron and 
 steel exposed to the weather. The panel at the 
 present time is covered with rust beneath the sur¬ 
 face of the film, and in some places the rust has 
 broken through and disrupted the coating. The 
 
coating is very dark in appearance, having fogged 
 considerably through the action of light. 
 
 Panel No. 7, painted with Zinc Lead, is streaked 
 with dark brown rust wherever the brush marks 
 were formerly apparent. 
 
 At the beginning of the test Panel No. 9, painted 
 with American Orange Mineral, and Panel No. 
 10, painted with Red Lead, gave excellent service. 
 Until last year these panels were in perfect con¬ 
 dition except for a whitening of the surface which 
 is probably due to the formation of a coating of 
 white carbonate of lead, effected by the carbonic 
 acid of the atmosphere, giving to the panels a pink¬ 
 ish tint. On panel No. 9 there are several slight 
 rust spots appearing through the surface of the 
 paint. Panel No. 10 is slightly darker than Panel 
 No. 9, and has offered greater resistance to the de¬ 
 structive effect of the salt air. 
 
 Panel No. 12, painted with Bright Red Oxide, 
 and Panel No. 14, painted with Venetian Red, are 
 both in generally good condition, with the excep¬ 
 tion of a few rusty brush streaks on Panel No. 12 
 and a few slight corrosion spots on Panel No. 14. 
 
 Panel No. 15, painted with Metallic Brown 
 Oxide, is also giving very good service except 
 for the appearance on the paint film of several 
 eruptions of pin-head size, which have apparently 
 not broken through but which have lifted the 
 paint coating slightly in spots. 
 
 Panel No. 16, painted with Natural Graphite, 
 
 6 
 
shows several slight pin-head eruptions on the sur¬ 
 face, as well as several deep corrosion spots spread 
 about. Its surface is chalking considerably. 
 
 Panel No. 17, painted with Artificial Graphite, 
 is uniformly covered with large rust spots, which 
 are spreading over a wide area, and thousands of 
 small pin-liead eruptions. This panel is chalking 
 heavily, the chalked surface resembling stove 
 polish in appearance. The inferior condition of 
 this panel as compared with Panel No. 16 (Nat¬ 
 ural Graphite) may be accounted for by the fact 
 that Natural Graphite contains inert pigments 
 such as silica and iron oxide. 
 
 Panel No. 19, painted with Lampblack and 
 Barytes, is covered with small round pin-head 
 eruptions which have not yet broken through. It 
 also has a spotted and dull appearance and shows 
 considerable chalking. 
 
 Panel No. 20, painted with Willow Charcoal, is 
 the best appearing black of carbonaceous origin 
 upon the fence. It has a deep color and is show¬ 
 ing no corrosion nor chalking. 
 
 On Panel No. 21, painted with Gas Carbon 
 Black and Barytes, there is considerable chalking 
 with a few rust spots apparent. This type of 
 black, however, is superior in appearance to 
 No. 19. 
 
 Panel No. 24, painted with Ochre, is covered 
 with many small rust eruptions as well as several 
 very bad rust spots. The paint film has become 
 
 7 
 
brown, due to the corroded surface beneath. The 
 him itself, however, is intact. 
 
 Panel No. 27, painted with Natural Barytes, 
 has scaled, and the paint that is left upon the sur¬ 
 face is badly discolored with rust. 
 
 Panel No. 28, painted with Precipitated Barium 
 Sulphate or Blanc Fixe, is also scaling, and the 
 portion of the film that is intact is pin-holed, 
 stained, and streaked. 
 
 Panels Nos. 29 and 30, painted respectively with 
 Calcium Carbonate and Precipitated Calcium Car¬ 
 bonate, are covered with rust, no pigment being- 
 left upon the plates. At the start of the test these 
 panels chalked to such an extent that the chalked 
 surface was washed off by the rains before the 
 test had weathered two years. 
 
 Panel No. 31, painted with Gypsum, is of a dark 
 brown color and is showing several rusty streaks. 
 Its surface is entirely covered with small pin-head 
 eruptions. 
 
 Panel No. 32, painted with China Clay, is fairly 
 white, and although there are a few rust streaks 
 appearing, it is in fair condition. 
 
 Panel No. 33, painted with Asbestine, is in 
 similar condition to Panel No. 32, the rust streaks 
 being slightly more pronounced. 
 
 Panel No. 34, painted with American Vermilion 
 (Basic Chromate of Lead), is in perfect condition. 
 
 Panel No. 36, painted with Lead Chromate, is 
 streaked around the edges for a distance of six 
 
 8 
 
inches with thin lateral and horizontal streaks of 
 rust. The middle of the panel, however, is in good 
 condition. 
 
 Panel No. 39, painted with Zinc Chromate, is in 
 excellent condition. 
 
 Panel No. 40, painted with Zinc-and-Barium 
 Chromate, has developed a slight greenish tint and 
 a little chalking. Otherwise this panel is in ex¬ 
 cellent condition. 
 
 Panel No. 41, painted with Pure Chrome Green, 
 is in perfect condition except for the development 
 of a slight bluish tint along the edges. 
 
 Panels Nos. 44 and 45, painted with Prussian 
 Blue, are both in good condition. While Panel 
 No. 44 has developed a slight greenish tint, Panel 
 No. 45 is still evidencing a most brilliant main¬ 
 tenance of its dark blue color and gloss. 
 
 Panel No. 48, painted with Ultramarine Blue, 
 is entirely covered with rust, the paint having 
 chalked off completely. 
 
 Panel No. 49, painted with Zinc and Lead 
 Chromate, is in perfect condition, with the excep¬ 
 tion of a few slight rust spots. 
 
 Panel No. 51, painted with Precipitated Black 
 Oxide of Iron, is in good condition, with the ex¬ 
 ception of slight chalking. 
 
 9 
 

Photographic Views of Some of the 
 Panels on the Atlantic City 
 Steel Test Fence 
 

13 
 
 Panel No. 1 Detail Panel No. 2 
 
 Corroded White Lead (Basic Carbonate- April, 1912 Corroded White Lead (Basic Carbonate- 
 White Lead), Old Dutch Process White Lead), Quick Process 
 
 (Note how the heavy rust streaks follow the brush marks.) 
 
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 Panel No. 17 Panel No. 19 Panel No. 20 
 
 Artificial Graphite Lampblack and Baryites Willow Charcoal 
 
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 19 
 
 
 (Note excellent condition of rust-inliibitive pigment paints.) 
 
* 
 
 June, 1910 
 
 American Vermilion (Basie Chromate of Lead) 
 
 20 
 
Panel 6666 
 
 Corrosion pits on panel painted with stimulative pigment 
 
 June, 1910 
 
 21 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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