6 



FIELDIANA: TECHNIQUE, NO. 8 



and foreign matter. Keep in a tightly closed container when not in use. The 

 addition of a wetting agent will facilitate the application of the separator. 



If the powdered form of gum arabic is not available, use any other form by 

 weight, at the rate of % oz. avoirdupois for 1 oz. liquid or 30 cc. 



CASTING PROCEDURE 



(1) Cover the mold with the separator, being careful to obtain 

 a uniform coating. The method of application and the brush used 



THE CAST IS REMOVED, AFTER IT HAS BEEN SOAKED IN WATER. 



are the same as for a light coat of varnish. This is the most im- 

 portant single step in the whole procedure; unless a smooth clean 

 coating is obtained over the entire casting surface, it will be im- 

 possible to make successful casts. 



(2) Dry the mold and the separator thoroughly. 



(3) Fill the mold by spreading the casting material (semi-liquid 

 celluloid) over the surface with a spatula and stroking back and 

 forth a few times to obtain an even coating, without bubbles. Re- 

 move as much of the excess material as practicable from the surface. 

 If a wooden spatula is used the mold will not be damaged. 



