The Lost Wax Process

Star uses a process of bronze casting known as the lost wax method, a process that has been in use for thousands of years.

We use one of Star's sculptures, Bathing Beauty, to illustrate the lost wax process.

The process begins with Star creating the original sculpture in clay. She sometimes uses other materials, such as wax.

A rubber mold is then painted over the clay, capturing every detail Star has put into the clay. This mold will be used to create the editions.

Molten wax is poured into the rubber mold, creating a duplicate of the original clay of Bathing Beauty.

The rubber mold is carefully removed from the wax. The mold will be re-used to create the full bronze edition.

Once the wax is removed, a trained artisan touches up the wax to match the patterns of the original clay. This is known as chasing the wax.

Star personally reviews and approves each of her waxes before they are "sprued". She will often chase the wax herself. Each wax is treated as an original sculpture.

Spruing

Wax rods known as gates, are attached to the wax. The gates allow the molten bronze to flow evenly and prevents air and gas from forming in the bronze. A spree cup is added to receive the bronze.

Gates are attached to the ears.

Investing

The wax is then dipped into a liquid ceramic material, known as investment. This is repeated several times to create a ceramic mold.

Burn Out

The ceramic shell is fired in a kiln. The shell bakes, melting the wax, and leaving a hollow cavity - hence the term, "lost wax".

The ceramic shell is removed from the kiln and molten bronze is poured into the shell. The temperature of the molten bronze is approximately 2,100°F.

Breakout and Sandblasting

After the casting has cooled, the ceramic shell is carefully broken away to reveal the bronze underneath.

Fragments of ceramic shell are removed by sandblasting.

Pouring the bronze into the ceramic mold.

Assembling Bathing Beauty

Assembly and Finishing

The gates and sprees are removed from Bathing Beauty. The bronze is then re-chased by grinding, sanding, and polishing to make the bronze look like the original clay. Pieces are re-attached.

Bathing Beauty is sandblasted a final time to create an even surface for the patina.

Patina and Mounting

The patina is hand applied on Bathing Beauty using heat and chemicals. Several applications are necessary to create a particular color. The patina is then sealed under a wax coating.

Star will often mount her sculptures on a wood and marble base, adding to a finished sculpture.