PAINTS, DYES, AND VARNISHES 



Larger quantities of driers impair the lasting qualities 

 of a paint, and should not be used except in places where 

 the rapid drying of a layer of paint is of more importance 

 than its durability. 



Some vehicles, such as turpentine, act as rapid driers, 

 but are not considered as u driers" in the generally ac- 

 cepted commercial use of the term, which applies to 

 such substances as red lead, monoxide of lead, the acetate 

 or borate of lead, one of the manganese salts, or one 

 of several zinc or iron salts. These may be used 

 separately or in various combinations, and are the basis 

 of the numerous "patent driers" on the market, the 

 indiscriminate use of which has brought such sub- 

 stances into disrepute. 



While linseed oil is a relatively cheap substance as 

 compared with other drying and non-drying vegetable 

 oils, its cost is sufficient to lead to much adulteration 

 and to stimulate the search for cheaper substitutes. 

 None of these substitutes equals linseed oil, however, 

 although some mixtures of boiled oil, resin oil, and resin 

 or turpentine, are fairly good vehicles. 



Hempseed oil, while scarcely attaining the position 

 of a rival of linseed oil as a vehicle, is used extensively 

 in Russia where hemp is grown on a large scale. In 

 that country hempseed and linseed are usually mixed 

 together, so that the expressed oil is a mixture of linseed 

 and hempseed oil. As hempseed oil seems to possess 

 all the good qualities of linseed oil, the mixture is a high- 

 class paint- vehicle. In this country the cost of hempseed 

 oil for commercial painting is prohibitive. 



Poppy-seed oil has the advantage over linseed oil 

 [263] 



