Making the Master Mold
When the modeling is completed we need to make a mold so we can make a wax replica for casting. Go HERE to learn about the lost wax casting process. The lost wax casting process is over 5000 years old. There are many improvements, but the basics remain unchanged.
We are making a flexible plastic mold with a plaster backing (mother mold) so the flexible mold will retain it's shape. This technique allows us to pick up very fine detail while at the same time allowing a simpler mother mold.
The first step is to coat the tiger with the flexible plastic material. We use urethane mold materials. It is a two part system that is mixed together and cures at room temperature to form a tough, flexible coating. It has the consistency of peanut butter and cures in about 20 minutes. You have to move along so it will not set while you are working.
This is a shot of the tiger with the modeling modifications. The red stuff around his paws are clay dams to catch the mold material. A release material is applied so the plastic will not stick to the tiger. We want to get this thing off eventually and the plastic is like glue on anything not properly prepared.
This picture shows the tiger with the first two coats of plastic mold material applied. We will put 4 coats on to get a thickness of around 1/2".
From the front. Eventually the mouth will be filled with the mold material. Note the clay dams around the paws are now filled.
Next-Making the Mother Mold (plaster backing mold)
