Mold making basics: Silicone Block Mold

Block mold explanation. This is the most basic mold method for silicone rubber. This is a good method when speed is more important than overall cost. We used 73-45 platinum silicone for this particular mold. A cut block mold like this works best with rubber that is shore A20 or higher. This means a medium rubber. Soft rubber such as Gel-10 would be too soft and would distort at the seams.