Cleaning of base metal alloy is done by:
(A) Warm HCl (B) Cold HF (C) Cold H2SO4 (D) Sandblasting with aluminium oxide
(D) SANDBLASTING
Sandblasting is the process by which particles of an abrasive (usually aluminum oxide) is projected at high velocity using compressed air in a continuous stream. The casting is held in a sandblasting machine to clean the remaining investment from the surface of alloy.