From Bronze Statues to Custom Silver Jewelry: the Lost-wax Method

The lost-wax method is a method of casting metal that has been in use for six thousand years. Virtually unchanged since used by the ancients, the method is used today to create such pieces as bronze sculptures, custom silver jewelry, dental work, or even auto parts.

“Cire perdue,” or lost-wax, is a method of casting metal that has been in use for over six thousand years. In essence, it involves the pouring of metal into a mold created from wax, resulting in complex forms otherwise impossible to create. The lost-wax method is used today to create such pieces as bronze sculptures, a silver pendant, a gold dental crown, or even an alloy auto part.

The lost-wax method is the best way to create intricate designs in metal, it is commonly used for making elaborate custom jewelry. Technology and tools have advanced of course, but the method is essentially the same as it was when used in Ancient Egypt.

The artist will first sculpt his masterpiece out of clay, wax, or another malleable material. Then, the model is encased in plaster or fiber-glass to create a mold. An inner mold will often be created at this time as well, by pouring liquid rubber around the model. This preserves the finest of details, important because when the plaster is broken apart, the original model is usually destroyed.

When the two halves are placed back together, the result is the master mold. Inside is empty space, a “negative” of the original. Hot wax is then poured into the space to coat the sides. Depending on how large the piece, a number of coatings may be needed. The hollow wax copy, an almost perfect replica of the original, is then removed (multiple copies can be created at this time).

The wax copy is then “chased” using heated tools to remove the seams where the mold came together. Each copy is carefully “dressed” to hide any remaining imperfections.

Next, “sprues” are attached to the piece, which are basically small wax rods that will ultimately result in tiny tubes for metal to flow in, and air to flow out.

The wax replica is then coated in ceramic material and fired. At this point, the wax melts out, thus the term “lost-wax.” Negative space now remains (as well as the small pathways left by the sprues). Finally, molten hot metal can be poured into the mold into the exact shape of the original model.

The metal piece is also chased to remove any marks left by casting, and detailed to perfection. If in fact a bronze sculpture, this is when the final act of adding the color occurs.

The lost-wax method can be used with any material that will disappear (melt or burn away) and leave an empty mold. For example, some automakers make engine-block models out of a synthetic foam which will vaporize when heated. This complex process allows for the most minute detail to be fashioned into the most delicate of metals. This makes it ideal for custom jewelry.

When working with small pieces like jewelry the process slightly differs in that metal cannot just be poured into a such a tiny mold. Instead, liquid metal is injected into the limited space by centrifugal casting (a machine that uses centrifugal force) or vacuum casting (uses atmospheric pressure).

Artisans like Jewelry John use the lost-wax method to etch inspiration into their heirloom jewelry. They specialize in hand-crafted silver bells and silver pendants, and with intricate detail they convey emotion in beautiful custom silver jewelry. Such complex designs would not be possible without this ancient casting method.