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Is oogoo (DIY Silicone Putty) Oven-safe? Answered

Hello! I have a question for people who use oogoo, or generally DIY silicone molding putty made from 100% silicone caulk.

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!



1 year ago

fyi; what you are trying to do is illegal


4 years ago

I have used oogoo a lot for moulding, but never in the oven. Temperature wise it should be fine depending on the caulk. But I would rather use Milliput two part putty to mould with rather than than oven bake polymer clay, its stronger and cheaper. I find that many polymer clays that have to be baked become brittle over time and break down. I did cast a very large model using fiber glass resin for car body kits and that turned out perfect. I have also done it with car body filler putty and that too turned out better than I expected.


4 years ago

Thank you both for the info and advice!

I think the acrylic paint in part is to make it easier to see the mold's details by introducing an opaque pigment, but also to introduce water into the mix to help it cure, so I think I can easily replace that with a drop or two of water or maybe even food colouring.

As for the baby oil, I couldn't find too many explanations behind it, but judging by how making it went, as well as how the silicone looked after it cured, it's probably meant to keep it from sticking to your hands, as well as to serve for debonding from some surfaces?

I've seen people use vegetable oil instead of baby oil for making oogoo. Would that be a safer alternative if I were to bake it, since it's basically a food product?


I'll look into contacting the manufacturer. Thanks for the tip. :3


Reply 4 years ago

To be quite honest I never used oil in my projects, just pre- hydrated corn starch and a fast working speed.

The only real benefit I can see is that the oil makes it a bit easier to get the mold into the right shape without the silicone being extremly sticky.

Nothing really sticks to silicone so it won't have an effect on releasing any material from the mold.

Just put a little amount of your baby oil in the oven, heat to 150° and check what happens to it - if nothing and no stink it is fine.

Similar for the paint if you want to use it.

If I need some color in my silicone projects I simply use colored chaulk instead of corn starch ;)


4 years ago

I would be worried about the paint and oil, not so much about the silicone itself.

No idea why baby oil would be used anyway and the paint is for the color?

Go back to the basics and made a putty with just chalk and things that evaporate during curing, like water and alcohol.

With a basic recipe I am next to fully certain nothing will happen till around 130-150° celsius.

Would no go higher than 160 unless it has to be.


4 years ago

If the tube says it's OK to 205C, then using it at 110C should be no problem. You will be under the maximum temperature by a very safe margin.

The best way to be sure, though, is to contact the manufacturer - there should be a customer service number email address somewhere on the packaging, or you can google for their website and get contact details from there.

Be very clear and direct with your question: If I expose the caulk to a temperature of approximately 110C, for X hours, will any harmful or toxic substances be released or emitted from the caulk?