I sculpt in water based clay on a wooden armature stand. The first day of work on a new sculpture is to build the wooden armature that will hold up the weight of the clay as I apply it. The first day with my model, much of the day is spent choosing the exact pose I would like to sculpt. Once the pose is right, I add clay to the armature at a fierce pace - massing out the head and locating the major features. Each day I must take care to keep the clay moisture at the right level, if the clay gets too wet it could slide off the armature, too dry and it becomes hard and cracks apart. The days go by, and with my model in front of me, I measure and add and refine. The further along the sculpture is, the slower my pace. Much time is spent looking at my model. I try to know the truth of her face so well that I can immediately tell if my sculpture is not quite right.
When I am finished working on the clay sculpt, I must mold the clay in order to reproduce the sculpture. This process will destroy the original clay sculpture, but the mold that is made will make it possible to reproduce the sculpture dozens of times in a variety of materials from plaster to bronze. It is very important to make a sound mold for any mistakes could mean that the sculpture is destroyed with with no way to reproduce it.
The first step in making my mold is to mix up a batch of liquid rubber and gently apply it to my sculpture, taking care that it finds its way into all the deep cuts and crevasses of the clay without forming air bubbles. This is the most important layer of rubber, as it captures the texture and detail of the surface and seals it safely from the effects of moisture loss. (See the photograph below)
After this layer dries, as second coat of rubber is applied, reinforcing the first. This second layer is photographed below:
After the second layer dries thoroughly, I mix a thickening agent into my liquid rubber and apply a third and a fourth layer to the piece, concentrating on creating an even thickness of about half an inch. I then apply a fifth layer of rubber to create a thick line around the sculpture where I will later cut the rubber mold apart. (See the photograph below)
The next layer is to thicken the rubber shell even more, especially at the cut line and deep recesses. This is mainly to ensure that when I put the hard shell over this, that it will not lock onto the sculpture due to too many undercuts - thereby making it impossible to make any reproductions of the sculpture. (See the photograph below)
Now the rubber application is finished and I must build a hard shell to encase the pliable rubber. This is done so that the rubber does not warp into a different position. I used a plastic paste for the shell on this sculpture because it would dry hard and yet be lightweight. I chose to create the hard shell in three parts, one large piece in the front and two in the back. In order to ensure that the hard shell would be easily removable and yet will lock together with ease, I created a wall of clay around the sculpture with an indentation in it that will help with registration. (See the photographs below)
Once the clay wall is complete, I brush a release agent over the entire surface and begin to mix the plastic paste. The plastic paste has a very short working life, so it is important that I apply it quickly or it will dry in the mixing container. (See the plastic shell photographed below)
This process is repeated with the two sections in the back, and it is allowed to cure for 48 hours. I then carefully remove the plastic shell and cut through the rubber along the thickened lines. I peel the rubber off of the clay and at last, it is done. (See the inside of the rubber mold sitting in it's plastic shell in the photograph below)
Now I can put the sections back together, tie it securely, and pour a plaster into the cavity to create a perfect reproduction of the original!
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