Monday, August 25, 2008

How Not to Cast a Face – August 25, 2008

Yesterday I somehow persuaded Sosia to allow me to cast her face with a skin-safe silicon casting product called Dermasil. I picked up Dermasil from my local sculpture shop Douglas and Sturgess. I know I’ve mentioned them before, but I love that store and the employees are incredibly helpful.

Casting a face can be tricky for several reasons: your model has to be able to breath, your model must hold their face totally still, and gravity is fighting against you as you apply the casting product. Most important to remember is the fact any time you cast someone’s face it is integral that you apply a release agent (e.g. Vaseline) to their skin so that the material you use to cast their face actually comes off. Always apply generously! Additionally, always ensure your model can breathe!!! There are three ways you can cast someone’s face.

The first way (and the cheapest) is using plaster gauze. It’s simple to do, but doesn’t take a great impression. All you need is the gauze and a bucket of water. Dip the gauze into the water, squeeze off the excess water, and start placing over your model’s face. The second way (more expensive, and less durable) is by using alginate. Alginate is the stuff that your dentist or orthodontist uses to make a mold of your teeth. Long story short, you mix up a batch then pour it over your model’s face. Once it sets you need to create a mother mold, which is like a support structure for the alginate because it is so flexible. A mother mold is made using plaster gauze. Just apply the gauze on top of the alginate that is set on the model’s face. Once it sets remove the mother mold first then CAREFULLY remove the alginate, place into the mother mold, then immediately cast a positive mold as the alginate will break down within an hour.

The final way one can make a mold of someone’s face is by using a skin-safe silicon (the most expensive). First, mix up a small batch of the silicon and paint a thin layer on your model’s face. Then mix up the rest and keep painting it onto the model. Once it sets, you’ll need to make a mother mold, and follow the same procedure as you would for alginate, however, the only difference is that silicon is good forever and you can cast your positive mold whenever you like.

This weekend Sosia and I used the skin-safe silicon method, but didn’t get good results. Unfortunately, the Dermasil was incredibly thick and hard to mix and measure, so rather than opting for a thin layer in the beginning, I decided to slap it all on at once. The Dermasil also set much faster than the label suggested, which was 15 minutes, and in reality it was only like 5-7 minutes. As a result, the Dermasil became really hard to apply, and actually would pull at other areas where it was nicely set. Then, when it came to demolding, it stuck a little to parts of Sosia’s skin and eyebrows. She applied a layer of Vaseline ahead of time, but I think because the Dermasil became so thick and hard to apply it actually pushed the Vaseline out of the way.

Next time, I’m going to try to Smooth-On “Body Double.”

1 comment:

Sosia Bert said...

I think that I will not be your model for the smooth-on. But, how are you going to find someone who hasn't read this post to be your next test subject?