Question

What is expandable moulding

Answer 1

hey!! 
here is your answer => 
first, let's understand what casting is! 
In metalworking, casting​ means a process, in which liquid metal is poured into a mold, that contains a hollow cavity of the desired shape, and then allowed to cool and solidify. The solidified part is also known as a casting, 
Expandable mold casting is a normal type of molding which is done by using things like sand, plastic, shell, plaster, and investment. This involves non-reusable moulds. 
hope it helps!