Mold-Making Tools

Clay

• The clay is used to take the initial shape of the mold. If you are taking a mold of a figure, you would press the model into the clay. Then use small balls of clay to add to the clay base. You should continue doing this until the clay reaches approximately halfway up the model. This is the cast for the bottom half of this two-part mold.

Clay Tools

• To make sure your mold comes out accurate you will need to do some precision shaping work. This can be done with a collection of clay tools, differently shaped knives and spatulas usually used in the practice of sculpting clay. In this case they are used to ensure the clay properly envelopes the model, to smooth out the top of this half of the mold and finally to cut away any clay that extends past the "detail seam," the term used for the halfway point where the two molds meet.

Rubber

• Rubber is what is used to make the final mold. Using styrofoam walls to surround the model, pour liquid rubber over the clay mold. The rubber will dry against the bare half of the model and form a tight mold as it dries. This is the actual permanent mold. You will remove the walls and the clay, flip the mold so that the rubber side is the bottom, and repeat the rubber-pouring process. You should now have two rubber mold halves.

Funnel

• Part of the mold must be open to allow you to pour material into the mold. To do this you can make some sort of funnel. You can make this into the mold when you are using clay to establish the shape of the mold. You can use anything funnel-shaped such as the cap of a pen and a cup. The object you use need not be a funnel itself as it will be removed from the mold anyway, simply something that will leave an impression that will act as a funnel.