The clay sculpture in our previous post is now ready to cast. This is a slightly involved process. See if you can follow along.
The mold making process is both a science and an art. We must get the ratios correct while being aware of how the opposite of what was carved will take the plaster. The first step was to check for severe undercuts that could rip off chunks of the mold causing imperfect casting. Then a wall is built around the original high enough to contain the silicone used to produce the mold and make sure this is water tight like a fish tank. The original sculpture is painted to lock in the oils that may seep from the clay. This is to prevent a chemical reaction between our mold material and the clay.
One of the lesser known techniques in mold making is to use water to determine how much of the mold mixture will be needed to fill your piece without excess, or even worse, not enough. Once the paint is completely dry we pour water to the top of where the mold mixture will reach then dump that back out to be measured. That volume will be calculated to accommodate the 10:1 mixture that is needed of the two parts used in making silicone molds. When the sculpture is dried it is coated with mold release, the silicone is mixed and pored over the original, then the whole thing is allowed to cure over night.
The photo above is the final product as far as the mold is concerned. The original clay sculpture was dug out of the cured mold and is now represented as the grey lumps you see surrounding it. This was filled with plaster and the next couple postings we do will show you the final steps.
We hope that wasn't too dry and are excited to show you the finished piece soon!
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