I fabricate my jewelry, but am interested in doing wax models for
casting. I want to do a hollow closed form shaped like a long pod,
but don't know how to make it so that the investment fills the
inside to keep it hollow. I know that I have to put at least 1 hole
in it, but how big does it need to be and does it need to be in a
Cast it in two parts and solder them together after cleaning. You'll
get a nicer finish that way.