Techniques

Much "off-the-shelf" jewelry is mass-cast or stamped. With handmade jewelry, a wide variety of metal crafting techniques may be used. The design typically lends itself to a particular technique, but many designs require multiple approaches. Each piece can present a new set of technical challenges depending on the fragility and placement of each stone and the intricacy of the design. Chains, clasps, and other fittings may also be handmade to create a special effect. The main techniques I use are described here:

  • Forging – A way of hand-fabricating a design by stretching, flattening, curving, and shaping the metal through hammering.

  • Lost-Wax Casting – Used to create soft, flowing lines or shapes that are difficult to form directly in metal. The piece is first sculpted in wax and placed on a conical stand. A metal sleeve or flask is placed around the piece, and the surrounding area is filled with an investment (a mixture similar to Plaster of Paris) and allowed to harden. The flask is then put into a furnace for many hours to burn out the wax—hence the name "lost-wax." This leaves a cavity in the investment in the exact shape of the model. Molten metal is then forced into the cavity using either a centrifugal casting machine or a vacuum. After the metal cools, the investment is removed by breaking the mold, meaning that specific cast mold cannot be reused. The metal must then be cleaned up and polished, additional design elements added, and the stones set.

  • Metal Clay – Known as Precious Metal Clay (PMC), this is a pliable material made of tiny particles of silver or other metals mixed with an organic binder. It has a consistency somewhere between modeling clay and Play-Doh and can be formed in innumerable ways. After it dries, it is fired in a hot kiln where the binder burns away, leaving solid metal. One texturing technique is to make a silicone mold of natural surfaces like oak bark or granite, then press the clay into it to impress the texture. At this stage, gemstones, metal bezels, bails, etc., can be added to the wet clay. The firing process shrinks the clay slightly, gripping any added gemstones or metal elements to effectively set them. After firing, the piece can be worked in traditional ways just like manufactured metal, and stones unable to withstand high kiln temperatures can be set afterward.

  • Piercing – Metal is sawed or cut away to form the design.

  • Repoussé, Chasing, and Engraving – Repoussé is the art of working with punches from the reverse side to push the metal into a three-dimensional shape. Chasing uses steel tools to push a pattern into the metal from the front; it can outline the repoussé design or add surface ornamentation by stamping. Engraving also adds decoration by cutting directly into the metal with a sharp tool.

  • Reticulation – The process of heating metal just enough to cause the surface to ripple and flow, creating a unique texture that cannot be duplicated.