Old fashioned rubber casting methods are just as effective as 20 years ago.
Chemical technology has caught up with rubber casting methods, making it simpler and faster. New clear rubber materials are easily poured and cut, saving time, according to Cast Craft. But many artists and crafters insist of the tried and true old fashioned rubber casting methods. You don't need to experiment with lots of unknown chemicals and curing times; these older methods work and have worked for many years.
Ceramic
The ceramic mold is an old method artists still use today. Anthony D. Bulone used this technique to create the first model of Barbie for Mattel in 1930, according to Laguna Clay. After creating a prototype, cover it with a commercial releasing agents or use liquid detergent or shellac. Place the prototype halfway immersed in water-based clay. Allow for the clay to dry and brush on a releasing agent over the clay and the prototype in the clay. Surround the entire mold with casting boards to seal the edges before pouring in fresh clay. Pour in liquid clay medium. Once it dries, use a hammer and screwdriver to carefully open. Remove the prototype and carve out a pour hole for adding rubber. Let the mold dry and cast with any type of rubber.
Plaster
A plaster mold is similar to a ceramic mold. Nail four wooden boards together to form a bottomless square box, open at two sides. Place it on a smooth surface. Pour in liquid plaster of paris half way. Place your model with a releasing agent into the plaster after about 15 minutes. Wait for the plaster to dry, then add a releasing agent to the plaster. Pour in fresh liquid plaster so the model is covered about 2 inches thick. After it is completely dry, the boards are removed and the model is opened with a screwdriver.
Latex
Latex mold making is another old fashioned casting method. Create a model in clay. Brush a releasing agent all over the model. If it is small enough, place it into a paper cup. Pour latex into the cup so it is completely covered. After it dries, cut away the paper cup. Remove the model from the bottom of the latex mold. Cut a hole into the bottom of another paper cup to pour your casting material. Place the latex mold in the paper cup with the pour hole. Turn the cup over so the pour hole faces up. Pour in the rubber and wait for it to cure. Release after it is dry.
Dental Alginate
Dental alginate is a mold making solution for dentists, but many artists also use it. It is a soft latex-like molding compound. Mix it one-to-one with water. It takes about 10 minutes to set, so you must work quickly. Use it to create a mold from the body or a model. It peels away easily and if needed, a pour hole can easily be cut into it. Use it to cast in rubber, plaster or silicone.
