Can you do platinum casting with a vaccum machine or does it need to be centrifigul?

Question

Platinum casting. Vacuum casting. spin casting. lost wax casting

Answer 1

what is best depends on how large your object is. Basically the smaller (cross-section) and longer the thinnest part of your piece is, the greater the benefit of using a larger force to get the metal into your mold.
For a lot of things vacuum casting gives pretty good results. I've done things like bronze casting of rose thorns (burnt out the originals) using vacuum casting and that came out great. I think standard rings should be fine.
I don't know if there is a lot of difference between different vacuum casting machines as far as the quality of the vacuum is concerned, though. And for vacuum you definitely need a metal flask (or something equally non-porous), but you probably have that anyway.
As I never done platinum, do you have to protect the surface of the molten metal from oxidation? If so, that may be an additional consideration, depending how you melt it down (induction or flame).