Materials and Formulas 209 



Asbestos 



Asbestos, dextrine, and whiting are the main ingredients in 

 mixing a batch of casting compound. 



Asbestos, also called earth-flax or mountain-cork, is a white 

 or gray mineral and has wide use in fire- and acid-resisting 

 articles. Plumbers and furnace men use it to insulate pipes. 

 For fish preparation, ground gray asbestos is best. It is an 

 inexpensive material and usually comes in 50-pound bags. 



Dextrin 



Dextrin is a carbohydrate found in nature in the sap of 

 plants. It has adhesive qualities and is soluble in water; it is 

 often used as a substitute for gum arabic. It also comes in large 

 bags and is inexpensive. 



Whiting 



Whiting is a finely powdered washed chalk which is used as a 

 pigment and for polishing. It also makes a fine "filler" in many 

 substances; it is inexpensive. 



FORMULAS 



1. Synthetic Casting Material 



Hysol— obtained from Houghton Laboratories, Olean, New 

 York. 



ERL 2795-4 parts 

 ERL 2793-1 part 

 Whiting-1M to 2% cups 



A jigger or two of asbestos will prevent flowing of the mix- 

 ture in the mold. 



