What is a good way to degas silicone mold material before pouring into the mold block?

Answer 1

I'll second mike1942f's reply, but add that in investment casting we'll also use a vibrating table in addition to or in place of the vacuum chamber. You can rig up a vibrating table fairly simply, but if proper care is taken in mixing and pouring the silicone then bubbles shouldn't be too much of a problem.

Answer 2

Silicone mold material should not require degassing if it has been mixed with care. It should give up any bubbles by careful pouring down the side of the mold. If you feel it must, the only practical way would be the kind of vacuum degasser used for investment casting.