Is oogoo (DIY Silicone Putty) Oven-safe?
I want to cast oogoo molds of lego bionicle masks with polymer clay, but my issue is I need to keep the clay inside the mold in order to prevent any kind of warping, as most of it is spread a little thin (1-2mm thickness) and I don't want to end up warping it even in the slightest.
Is oogoo or cured 100% silicone caulk oven-safe as long as it's within the specified temperature range? (I already know most DIY silicone putties aren't food-grade.)
The silicone caulk I'm using is GE all purpose silicone I, mixed with corn starch, acrylic paint, and baby oil. The back of the tube says that it should not be used on surfaces that will exceed 400F/205C. The polymer clay I plan on using is cured at 110C, so I don't think it'll be a problem, but I'm worried exposing the silicone caulk mold to high temperatures will cause it to release some harmful chemical compounds. I looked up an MSDS sheet for GE silicone, and they had a generalized one stating exceeding the maximum temperature will cause the release of formaldehyde. Since I plan on baking these in our kitchen oven, I wouldn't want harmful chemicals contaminating a space where we cook our food.
Also, if baking isn't an option, since the polymer clay is spread thin, and cures close to 100C, would curing it in boiling water be an option? (That way any water soluble chemicals would remain contained while the clay hardens.)
All help is appreciated!