Henley's Twentieth Century Formulas, Recipes and Processes

by Unknown

GYPSUM:

See also Plaster.

Method Of Hardening Gypsum And Rendering It Weather-proof.

Gypsum may be hardened and rendered insoluble by ammonium borate as follows: Dissolve boric acid in hot water and add sufficient ammonia water to the solution that the borate at first separated is redissolved. The gypsum to be cast is stirred in with this liquid, and the mass treated in the ordinary way. Articles already cast are simply washed with the liquid, which is quickly absorbed. The articles withstand the weather as well as though they were of stone.

GYPSUM FLOWERS: See Flowers.

GYPSUM, PAINT FOR: See Paint.