Things You'll Need
2-inch by 4-inch lumber
3-inch wood screws
Methyl Ethyl Ketone Peroxide (MEKP)
Sculptures made from fiberglass and resins have several distinct advantages over those made from concrete, bronze or other materials. They are significantly lighter, making them easier to transport and ship. Also, they are much more durable than concrete. Fiberglass sculptures can be placed outdoors, so they can be made much larger than sculptures constructed from other materials. Making a fiberglass sculpture is a time-consuming task, but it is a great way to create lightweight, long-lasting works of art.
Construct your sculptural model from modeling clay and coat it with petroleum jelly. Build a box that is 3 inches larger than your sculpture, and coat the inside of the box with paste wax.
Fill the box with 1 inch of plaster. Insert your clay model. Continue filling the box with plaster. Allow the plaster to harden for 30 to 45 minutes or until it is cool to the touch. Using a spoon or a palette knife, remove the clay from the plaster. Shellac the inside of the plaster mold and let it set overnight.
Brush paste wax along the inside of the mold. The paste wax should extend to the edges of the mold to prevent the plaster from sticking to the fiberglass.
Mix Bondo with its catalyst and add a small amount of fiberglass resin to achieve a paint-like consistency. Brush Bondo along the inside of the mold and let it set for 30 minutes.
Measure and pour fiberglass resin into a cup. Add 7 drops of MEKP to each tablespoon of fiberglass resin and mix. MEKP is a catalyst that activates the fiberglass resin and allows it to harden.Brush the fiberglass resin mixture on top of the Bondo. Lay squares of fiberglass matte along the inside of the mold, making sure that the pieces overlap. Brush additional resin on top until the fiberglass matte pieces are soaked through.
Allow the fiberglass resin to set up for 45 minutes, or until it is cool. Use a hammer and chisel to break away the plaster mold. The fiberglass cast can then be sanded, patched and painted.
Always wear rubber gloves when handling fiberglass matte. The fibers can cause intense itching if they come into contact with your skin.
Bondo and fiberglass resin emit harmful fumes. Construct your sculpture in a well-ventilated area.
MEKP is an explosive substance, so keep flames away from your work area when you are mixing and applying the fiberglass resin mixture.