PAINTS AND WHITEWASHES 229 



173. Brown Pigments. Umbers are ochres containing 

 a large amount of manganese. The best umber comes 

 from Cyprus; it is very permanent, has good covering 

 power, and mixes well with other pigments. It is neither 

 affected by acids nor alkalies and it is very cheap. 



Vandyke browns are mixtures of iron oxides and organic 

 matter. They are permanent, mix well with other pig- 

 ments, and have good body. 



174. Black Pigments. Lampblack, as well as the other 

 black pigments, has carbon for its basis. Lampblack is 

 permanent, of good covering power, and fine grained. It is 

 difficult to mix with water or oil and dries slowly. 



175. Mixing Paints. The main object in mixing paint 

 is to get every particle of the pigments in contact with the 

 vehicle. The pigments are purchased dry or in the paste 

 form mixed with a small amount of the vehicle. The 

 latter form is usually preferable, because the pigment has 

 been ground in a small amount of the vehicle in preparation 

 and its dilution is easier than the suspension of the dry 

 pigment. 



A small hand mill can be purchased for about $10 that 

 is satisfactory for mixing paints. For small jobs the ready 

 mixed paints are more economical. 



176. Whitewashes. Government whitewash is prepared 

 by slaking one-half bushel of good quicklime in hot water, 

 keeping it covered while slaking. Strain and add 4 quarts 

 of salt, dissolved in warm water, 3 pounds of ground rice 

 boiled to a thin paste, \ pound Spanish whiting, and 1 pound 

 of clear glue, dissolved in warm water. Mix and let stand 

 for several days. Keep the wash thus prepared in a kettle 

 or portable furnace, and when used put it on as hot as possi- 

 ble with a painter's brush or a whitewash brush. This 

 wash may be made in quantities and heated as needed, but 

 it should be put on hot. 



Factory whitewash is used for interior work. Slake 1 

 bushel (62 pounds) of quicklime with 15 gallons of water; 



