Ive used Smoothon body double platinum cure silicone to make good
copies of various fingers, and other general molding stuff.

I even used it to cast a bit of 63/37 solder, didnt come out perfect
but it didnt melt or make any bad smells.

Air bubles in it like to stick at corners sometimes, I suspect using
the proper mold release they suggest would fix that however.

On 11/22/08, Danny Miller <dannym@austin.rr.com> wrote:
> Pressure does not de-gas, what it does is force the bubbles into
> solution but AFAIK you still need to de-gas first or there will be too
> many bubbles, and too large.  I'm sure it depends on what resin we're
> talking about.  High viscosity resins are difficult to get bubbles out of.
>
> You need to vac in a different container typically.  I tried to pour
> into a mold and vac and there were bubbles coming up that were clearly
> too many to have been from the already degassed urethane I just put in
> (pouring often traps small bubbles between the resin and mold and I
> wanted it out, plus I needed it to flow into an undercut which kept
> trapping air).  The silicone mold itself had trapped air that was coming
> out apparently, and it seemed to have no end.  Plus it'll loft up and
> overflow your mold.
>
> So you generally can't vac it after it's in the mold, but your
> previously degassed solution is no longer completely bubble-free after
> pouring.  That's where the pressure casting comes in, pressure is not a
> problem for the mold.
>
> Do not use tin-cured silicone molds in a heated oven.  It breaks down in
> a few cycles..  You need the more expensive platinum-cure.
>
> http://www.smooth-on.com/ are the guys to deal with.  Lots of products,
> very knowledgeable, carry mfg specs, good prices.
>
> A lot of other suppliers buy their stuff or the same stuff from their
> mfg, relabel it, and don't know crap about it and have no specs.
>
> Danny
>
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