Epoxy release from silicon mold?

Like any other mold its best with mold release.

Hard to say. Usual 'mold release' is basically spray wax. Some epoxies will dissolve small amounts of oil, wax, or grease (don't know about West Systems). Some will even entrain water (so they stick to poorly cleaned surfaces, of course).

A bit of talc or graphite, if it sticks to the silicone, won't dissolve, and hurts the bond. Or, maybe grease it and flour it like a cake pan.

Silicones aren't all the same, either; there's the polymerized dimethylsiloxane, and some kind of filler. The filler might matter.

Start some trials, a little wax dissolved in paint thinner and applied with a cotton swab would be my first experiment.

I've got some left over from my table project and want to make granddaughte r some pendants.

Another option is to call West System and ask their opinion. Yesterday, I bought new vulcanized rubber tires, for my bandsaw, from Carters. I was n't sure if G-Flex 650-8 epoxy would adhere to vulcanized rubber, appropria tely, hence I might have to order Carter's 3M epoxy. I called West System and asked their advice. I was assured the G-Flex would work, appropriatel y.

If you know some specific info about the silicone, I suppose that would hel p with West System's advice. I would think they may know what's best to a pply to the mold, to allow for release, if need be.

Sonny