Sculpting Techniques for Lost Wax Method

Indirect Method

• Sculptors, not wishing to work directly with wax, will first sculpt their models in clay. Once the clay model is completed, a mother mold is made over the original model. The mold will have multiple pieces that will be taken off the clay and reassembled. Hot wax is poured into the mold and slushed to form a hard wax copy of the original clay.

Direct Method

• Artists working in the direct method will sculpt the wax directly, skipping the step of making a clay model. Jewelry artists will start with a block of hard wax and carve in a subtractive technique. Sculptors working in a larger format will work with a softer wax in an additive method over an armature.

One-off Casting

• Artists sometimes make a one-off sculpture making a single sculpture from a single unique wax. The direct sculpture method is used and no mold is made. The wax is prepared with sprue. Spruing is the process of adding sticks of wax to the highest points of the sculpture to provide space for the molten metal to flow. The wax is dipped in a liquid mold material to form a shell. The wax is then burned out and the original is lost. The mold is destroyed when it is chipped from the cooled metal.

Hard Wax Modeling

• Wax is graded by hardness. Artists wishing to work with fine details choose the hardest wax. Hard wax can be machined, cut and carved with gouges, rasps and power tools. Hot tools can also be used by holding the hand tool over a Bunsen burner. Hard wax is favored by jewelers.

Soft Wax Modeling

• Victory brown wax is a soft wax used by sculptors in a way that is similar to clay. It is very forgiving and is used in both additive and subtractive methods. An armature is often used and softened clumps of wax are added to it. As the model is fleshed out, subtractive methods are used to add detail.

Armatures

• When an armature is used in soft wax modeling, it can be made from sticks, paper and twine to be burned out along with the wax. If the armature is built with a non-flammable material, the wax will have to be cut off the armature and reassembled. The seam lines and any damage will be repaired with additional warm wax and burnished.