A brush on mold is essentially two flexible rubber halves held
in form by a rigid material known as a mother mold. Making a 2-piece
brush on mold is ideal for sculptures that have 3 dimensional detail,
such as a bust. There are many brushable mold rubbers and gypsum
or resin based materials on the market you can use to make your
mother mold with. Each material has different properties, be sure
to find out which materials will be the best for your specific project.
To make the best choice, you will want to consider several factors:
flexibility, working time, cure time, viscosity, and of course price.
In addition, you should consider several basic questions; What your
original is made of and does it have any under-cuts? What material
you want to cast into the mold and how many casts you need? How
much time do you have? And what materials you prefer, if any. Following
is a detailed list of the steps necessary for creating your mold.
For this mold we are using silicone mold rubber, thickened for
brushing and a fiberglass reinforced polyurethane for the mother