CHAPTER VI 

 THE SCOPE OF PRACTICAL PAINT TESTS 



The Pigment Contention. During the year 1906 officials of 

 the North Dakota Agricultural Experiment Station examined 

 a number of paints on sale in the northwestern States. The 

 presence of large quantities of inert pigments as well as water, 

 in some of these paints, prompted agitation for State laws 

 requiring the formula-labeling of paints. Certain paints made 

 of white opaque pigments such as white lead and zinc oxide were 

 exempted from the statute. The white opaque pigments used 

 in these paints were believed by certain manufacturers as well 

 as by many prominent paint authorities of high standing to be 

 benefited in their wearing value by the addition of small per- 

 centages of inert crystalline pigments, such as barytes, silica, 

 China clay, etc. Laboratory experiments had already deter- 

 mined that these inert crystalline pigments had a certain defi- 

 nite action in increasing the life of paints, but it had become 

 evident that they should be used with discretion, in moderation, 

 and with a proper understanding of their limitations, if the 

 best results were to be obtained. The addition of very large 

 quantities of such pigments was not indulged in by discriminat- 

 ing manufacturers, but the exact percentage to use was a matter 

 of great doubt, even to the most experienced. In order to 

 determine just what percentage of crystalline pigments, admixed 

 with white opaque paint pigments, would give the best service 

 and results, it seemed imperative that practical paint tests should 

 be made. A series of paint tests on commercial brands of paint 

 had already been started at the Fargo Agricultural College, 

 and, at the suggestion of the Paint Manufacturers' Association 

 of the United States, another series of practical paint tests were 

 instituted, and carried out under the supervision of Dr. E. F. 

 Ladd, Director of the North Dakota Experiment Station. 



Test Fences to Solve the Problem. It was apparent that 

 the pigment question could be solved only through field tests 



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