134 PAINT TECHNOLOGY AND TESTS 



of the composite paints was due to the action of the other pig- 

 ments in these combination paints in preventing the lead from 

 chalking away. 



" The Committee finds that the addition of a reasonable per- 

 centage of zinc oxide to white lead increases its durability and 

 retards its chalking, renders it whiter, and forms a surface that 

 presents a much better repainting condition. The combinations 

 of white lead and zinc oxide on the Atlantic City Test Fence 

 were in general good condition throughout. 



" Corroded white lead, sublimed white lead, zinc oxide, and 

 zinc lead are the standard white opaque pigments. They were 

 all tested on the Atlantic City Fence and it was found that to 

 use any one alone results in inferior protection to the wood. 

 Barium sulphate, silica, asbestine, china clay, and calcium car- 

 bonate are the standard crystalline pigments. In the past, 

 the overloading of paints with these crystalline or inert pigments 

 has been the cause of the prejudice that painters have had 

 against their use. It has been established beyond controversy, 

 however, that the use of these pigments, in moderate percentage, 

 combined with any of the standard opaque white pigments, 

 such as white leads, zinc oxide, etc., undoubtedly results in 

 better service from every standpoint and forms the most satis- 

 factory white paint for general outside use. Some of the most 

 perfect painted surfaces on the fence were those made on the 

 above basis as reference to the charted report will show." 



