Q: I want to make a mold of my face, but I don’t know how. Do you use plaster?
A: It is very difficult to make a cast of one’s own face. I’ve made molds of all kinds of things, but have not attempted this. Even making one of another person’s is tricky. I would definitely not recommend this as a first project in life-casting. If you really want your life-mask made, have an experienced person do it for you.
If you want to mold somebody else’s face, work up to it slowly. Start with inanimate objects, then a hand or foot; only when you have mastered the technique should you try a living face. Although some sculptors have made molds by putting plaster directly on a person’s skin, this is a dangerous thing to do; bad burns can result from the exothermic reaction of the plaster’s setting. I can only imagine the scene when you realize that this hard and heavy plaster thing that is covering your face won’t come off, and it is getting hotter…
I have seen fiberglass casts with all the model’s body hairs in place—the plaster pulled them out when the mold was removed (ouch!); the fiberglass positive then pulled them out of the plaster. In the recommended process, the mold is made from dental alginate, which is available in warm water and cold water versions. If you don’t like goosebumps on your castings, the warmwater kind is preferable. The mold material is a powder which is mixed with water and stirred into a paste, which is applied as quickly as possible—it sets within three to five minutes. The material when set is a flexible gel which peels off skin readily—no release is necessary for skin that is not densely haired. It should be masked off from head hair.
The mold may need a supporting shell to faithfully retain the form of the part being molded. These may be improvised from plastic containers or built up with plaster and cloth, which takes longer. When the mold is taken off the model, plaster is poured in, and left to set. If a permanent mold is needed, then this first plaster positive is used for a master in the RTV rubber mold-making process. Subsequent castings from the alginate mold will be progressively more degraded, due to cuts, tears, and general erosion.
The alginate—usually the cold-water version—may be purchased at dental supply houses, or one can obtain it from sculptor’s supply places like Johnson Atelier, 800-732-7203; Douglas and Sturgess, 415-421-4456; and a place in Vermont that specializes in life-casting supplies (even instructional videos): Pink House Studios, 802-524-7191.