| The following is my procedure for molding any large reptile. In
these step-by-step photos, I am molding a 150-pound alligator snapping turtle. RTV (room
temperature vulcanizing) rubber compounds are made to work best at 70 to 80 degrees.
Therefore, they will not set up as fast on frozen specimens. Set up time, at normal
catalyst of 10%, is about 30 to 45 minutes at 70°F. The product chosen for this project,
Smooth-Sill 912, is made by Smooth-On, Inc. Smooth-Sill has a regular 10% catalyst with an
accelerator additive that will kick off rubber in 5 to 8 minutes, even on a frozen
specimen. Also offered is thi-vex, a thixotrophic additive that will thicken silicone from
a honey consistency to the thickness of bread dough. Both of these products were very
important to this project. Due to the size of the turtle, a block mold would require many
gallons of rubber and would be difficult to unmold. Therefore, a skin mold was the best
choice. Precise measurements are required for mixing catalyst into rubber, and a very
accurate scale is necessary... |
 Step 1: Positioning. Position
the specimen on a piece of plywood large enough to give some working room around the
edges. Place the specimen in freezer, checking frequently until the desired position is
achieved. Freeze solid. |
