How to Make a Silicone Orc Mask Part 2: Urethane and Plaster Mold

< Go Back to Part 1

Orc Goblin Silicone Mask Sculpture (8)

I made a brush-on silicone mold of the orc sculpture I created the other day.

two part urethane and plaster mold for silicone mask of an orc (1)First, I bought some two-part urethane 70-20 mold making rubber and mixed it 1:1.  Gotta make sure you use a decent mixing container –preferably with see-thru measurement gauge on the side.

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:

mold silicone mask

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).

> Go to Page 3 : The Silicone Mask

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.

urethane mold for silicone mask

VN:F [1.9.20_1166]
Rating: 5.0/5 (1 vote cast)
How to Make a Silicone Orc Mask Part 2: Urethane and Plaster Mold, 5.0 out of 5 based on 1 rating
Jason Sipe Jason Sipe (68 Posts)

Jason Sipe is an artist, craftsman and writer. He has spent the last 20 years working in the art and media fields. He now turns to this blog and helping others learn about creating art as his main focus.