I made a brush-on silicone mold of the orc sculpture I created the other day.
I made my first couple layers runny, so as to pick up all of the details in the clay–especially the rotten and mottled skin texture. Only mix about 8-10 oz. (4oz part A to 4oz. part B) to do each layer. Once it gets a bit tacky, it’s good to start mixing the next layer–this stuff kind of needs to be layered up before it cures fully, or you risk de-lamination.
After about two solid layers of runny, I added some fumed silica to it to thicken it up.
Here is the first video of the mold-making in progress:
NOTE! Wear a mask and mix this stuff outside if possible–it creates little clouds of dangerous silica particles that are very toxic to your lungs (I found this out the hard way).
After making about three layers of the thickened urethane, especially in areas like the eyes, nose chin, ears, and around the neck, I let the urethane dry and cure overnight.
Then, I added an ultracal 30 plaster mother mold in two parts, using fiberglass mat for a strengthening material. This is a task you shouldn’t undertake without watching several videos. I’d recommend Mitch from Brick in the Yard on Youtube. He’s a genius.
So, once I pried apart the mother mold, then slit the back of the urethane mold from the clay sculpture, I de-molded it and got two separate parts.
So far, so good! I’m VERY excited to add silicone into this mold and add the mannequin armature back into it to make it fit a human head a bit more snug.
This is all an experiment, so you might want to see the next part before you follow any of my advice.