A resin sculpture is a statue or other piece of three-dimensional art that has been cast using fiberglass resin. Resin is a fairly lightweight, durable material that can be painted and glazed to look like stone, porcelain, bronze or marble. It is used to manufacture a wide variety of products. For art, resin’s relative cheapness compared to other materials makes it desirable when the artist wants to make multiple copies of a sculpture. Resin also has become a popular material in creating small statues, jewelry, figurines and various collectibles.
The resin itself is a mixture of materials, including urethane, silicone, epoxy and polyester. Resin sculptures are hardy but not indestructible. Cold, freezing conditions can cause resin to crack because the material contracts, then it expands when the temperature rises. Any resin sculpture kept outside should be brought indoors during cold weather.
The process of making a resin sculpture begins when the sculptor creates an original model in clay, wax or other material. A mold is made from the sculpture by covering the model with liquid molding material. Popular molding materials include silicone, rubber and plaster. The sculpture might need to be coated with a separating agent such as petroleum jelly to ensure that the mold can be removed fairly easily. Silicone is a highly desirable molding material because it requires no separating agent.
When the casting material dries, the mold is removed from the model. The mold is separated along one or more parting lines, creating distinct molds for the different parts of the sculpture. For resin sculptures, molds made of rubber, silicone and other flexible materials often are adequate for casting. More rigid materials, such as metal, wood and plaster, also can be used to make molds. The inside of the mold might need to be painted with polyvinyl alcohol or powdered with talcum to ensure that the resin sculpture can be removed.
When the time comes to cast the resin sculpture, the liquid resin mixture must have a catalyst added to begin the hardening process. Commonly used catalysts include methyl ethyl ketone peroxide, which can be highly volatile, and the less-hazardous benzoyl peroxide. One problem that often occurs during the casting process is the presence of air bubbles in the resin. Air bubbles can be managed by mixing in powdered bronze or similar materials and by ensuring that the mold is vented toward the top so air can escape.
The most commonly used type of resin is polyester, which is normally greenish and glass-clear when cast unless a coloring tint has been added. Figurines commonly sold in stores often are cast in polyester resin. Polyester resin is toxic and produces a terrible odor, so adequate space, ventilation and other safety measures are needed. The clear and more durable epoxy is probably better for artists working at home, although epoxy tends to be more expensive. Silicone and urethane resins are prized for their flexibility, although urethane’s odor during the casting process can be particularly unpleasant and will always remain detectable on the finished work.