You won't need any kind of mold release with silicone as it sticks to only itself. (However, if you're paranoid or unsure the substance you used to make the cast object will stick to silicone, you can use Pam or some other kind of resin mold release. Don't use vaseline, as it will create an unwanted texture on the cast object.)

Pour the mixed silicone slowly into the box containing the object you want to cast. If it doesn't fill up all the way, just mix another batch of silicone and keep filling the box until you cover the object completely.

The stuff I'm using takes 24 hours to cure. After that time, it's a simple matter of dismantling the foamboard box and taking the newly created mold out.

You'll find the silicone extremely rubbery and easy to pull away from the walls of the box...

Turn the mold over. Take a craft knife and carefully trim away any excess silicone which may have leaked out over the object...

Pull the object free of the silicone. (This should be MUCH easier to do than it would have been had we made the mold out of latex.)


Next: Casting with Silicone...