Applying Paint Coatings

TABLE 16.1. Effect of Surface Preparation of Steel on Life of Paint Coatings [9] 

Surface Preparation Durability of Paint (years) in Sheffield, England 

Only in unusual cases should paint be applied over a damp or wet surface because poor bonding of paint to steel results under these conditions. A second prime coat can be applied after the first has dried, or a sequence of top coats can follow. A total of four coats with combined thickness of not less than about 0.13 nun (5 mils) is considered by some authorities to be the recommended minimum for steel that will be exposed to corrosive atmospheres [10]. 

One of the advantages of this process, compared to spraying, for example, is that it results in a uniform, thin coating [about 25 pm (1 mil) thick] with coverage on both exterior and interior cavity surfaces. In addition, this process is controllable, automated, efficient, and environmentally acceptable [12]. 

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Radiometric Evaluation of the Effectiveness of the Chromic Acid Rinse Treatment for Phosphated Work , US Department of Commerce, Office of Technical Services, Rep. No. PB 111,397 (1952) A Study of the Effect of Chromic Acid and Chromic-phosphoric Acid Rinse Solutions upon the Subsequently Applied Paint Coatings , US Dept, of Commerce, Office of Technical Services, Rep. No. PB III, 578 (1954)... 

The fundamental difference between test chambers and cells is that samples are placed within test chambers whereas test cells are placed onto the emitting surface of a product or material. Emissions cells are limited to planar materials or applied paints /coatings and cannot be used for moulded or nonplanar materials. However, they are inherently quicker and easier to use than chambers and eliminate the... 

Uses Defoamer for chemical compounding, syn. or water-based metalworking lubricants, aq. systems, Inks, janitorial applies., paints, coatings, paper industry, waste treatment, severe foaming applies. Features Highly compat. dilutable with water Foamkill CPD [Crucible]... 

Uses Surfactant for household/industrial detergents and cleaners, textile applies., paints/coatings, lubricants, emulsion polymerization, and metal treatment... 

Uses Solubilizer, cleaning agent for industrial and household detergents/ cleaning agents, textile applies., paints/coatings, emulsion polymerization, lubricants, and metal treatment Properties Pellets HLB > 15 sapon. no. 45 nonionic Hedipin-PS/300 G [Dr. W. Kolb AG]... 

FIGURE 9.7 Effect of crater formation on appearance of a paint film. Craters were supposed caused by spreading from drops of low air-oil surface tension insoluble fluid over the surface of freshly applied paint coating. (Reprinted from Prog. Org. Coat., 3, Bierwagen, G.R, 101. Copyright 1975, with permission from Elsevier.)... 

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