Tuesday, April 15, 2014

7 Leaf Cuff in Progress

The most popular item on my display during both wholesale shows earlier this year was the 7 Leaf Cuff shown below. I thought it might be interesting to show how this bracelet is made.

7 leaf cuff
Vickie Hallmark

The right and left curving leaf master models were made by hand in sterling silver metal clay, with my signature leaf vine texture. After firing in the kiln in two different stages as high as 1500ºF, the pieces are reduced to sterling silver. After polishing to provide the best surface, they are soldered to metal attachment rods called sprues and then molded with heat curing rubber. The rubber molds are cut open along the edges to remove the masters and then wax is injected into the molds repeatedly.

7 leaf cuff components
These wax copies are attached to a center wax sprue to form a tree of waxes, which is then molded itself in silica based investment (like hard plaster). After burning out the wax in a hot kiln,  Argentium silver is melted in a crucible at the center of a centrifugal casting machine, the mold is place at the end of a long arm, spring wound to spin freely. When the metal is melted, the crucible is pushed up against the opening to the mold and the spring is released to force the metal into the void in the mold. After cooling, removing the investment, cutting the pieces apart, and minor polishing, the pieces are ready to assemble, as shown above.

7 leaf cuff fused flat
Each leaf is dipped into flux, carefully positioned with its neighbors in a long line, and then each joint is  fused together without any solder. The bracelet is ready to form around a mandrel and heat harden (a specialty feature of Argentium) to maximize its strength before it is polished and patinated to bring out the texture.