A few weeks ago, I promised I'd post more information on neoprene, a latex-vinyl liquid that can be poured into plaster molds for forming puppet parts and props.
Sculpt puppet head in WATER-BASED clay. (This is very important.) Make a plaster mold from the clay head. Clean the mold with soap and water and rinse thoroughly. Note: Neoprene will not "set" if it comes into contact with oil or grease of any kind, so the mold must be very clean. This is also why oil-based clay can't be used.
When the mold is dry, plug the seams with water-based clay. Pour neoprene into the mold up to the top. (As time passes, the mold will absorb water out of the liquid neoprene, eventually leaving a "skin" wich cures to a hard plastic-like material.) During the first 20 minutes or so after adding neoprene to a mold, the level of the liquid neoprene in the mold will drop, so you will need to "top off" the mold by pouring in more neoprene.
Leave the liquid neoprene in the mold for about 5 hours for a 5-inch puppet head. Then pour the excess liquid neoprene out of the mold and back into its original container, so it can be used again for another project.
The cast (stil inside the mold) will cure overnight at normal room temperature. Or, place the mold in a sightly warm (150 degrees F) oven for a few hours. When the cast is no longer sticky to the touch, it can be removed from the mold. The cast will be soft and pliable for about an hour after removal from the mold. This is a good time to cut off excess bits of material at the parting line. After several hours, the cast will cure to a very hard, plastic-like material. Note: The cast shirnks 10% during curing. So the final puppet head is only 90% as big as the original sculpted clay head.
You can purchase neoprene from:
5901 Telegraph Rd.
City of Commerce, CA 90040-1636
phone: (213) 724-6161
Ask for product #RD1126.
The last time I bought some (which was three years ago), neoprene was sold in 1-gallon or 5-gallon containers, or drums. One gallon cost $50.00, a 5-gal container was $150, and a drum was $16 a gallon. (Drums contain some huge amount.)
I have found that neoprene has a two-year shelf life, though others have told me the shelf life is indefinite. I usually buy only one gallon, and I get 10-15 puppet heads from it.
One word of caution: if you live in a cold climate, don't attempt to have neoprene delivered to you in the winter. If it freezes, it's wrecked, and Mydrin won't accept responsibility for the failure.