bronze casting

Tim Nimmo of Crow Atelier pouring molton bronze for Sumichrast's "Swimmer".
Tim Nimmo of Crow Atelier pouring molton bronze for Sumichrast's "Swimmer".


Jözef Sumichrast's bronzes are sculpted in clay, wood, cardboard, "plaster" or a combination of these and other materials. Seeking quality and perfection, he works on each sculpture throughout the entire casting process. This method sometimes takes a year or more. The process takes a dozen steps and the skill by numerous artisans at the foundry.

Working clay sculpture of, "Swimmer", Loveland, Colorado.
Working clay sculpture of, "Swimmer", Loveland, Colorado.

The Lost Wax Process (Cire Perdue) The lost wax process is a method for changing the original "soft sculpture" into bronze. Changing the original piece involves making two molds for each sculpture. The Master Mold (first mold) The first mold is called the master mold because it is taken from the original. This mold is made from a special rubber supported by a plaster shell. The rubber registers the exact form and details sculpted in the original. When the original is removed from the master mold the resulting space is filled with hot wax. Skillfully pouring the wax will determine the thickness, and therefore the weight of the bronze sculpture. Jozef Sumichrast

Rubber coating covering the clay sculpture. Cards are added to create a seam for the mold.
Rubber coating covering the clay sculpture. Cards are added to create a seam for the mold.

Plaster is applied over the rubber coating for support and tabs lock the rubber in place.
Plaster is applied over the rubber coating for support and tabs lock the rubber in place.

The rubber liner is peeled away from the clay, which will be replaced with wax.
The rubber liner is peeled away from the clay, which will be replaced with wax.

The Second Mold. When the wax has been chased or reworked to perfection it is encased in a second mold. This mold is made of ceramoc material that can withstand the 2,000 degree temperature of the molten bronze. The second mold is placed upside down into the foundry furnace to melt out the wax. Molten bronze is now poured through "pouring gates" into the cavity left by the "lost wax" Jozef Sumichrast

Metal Chasing. After the coolong process the mold is carefully hammered apart to expose the bronze casting. A grinder removes the "pouring gates" and welding, grinding, filing and sandblasting the surface perfect the bronze. Jozef Sumichrast

The cast bronze is being refined in preparation for the patina.
The cast bronze is being refined in preparation for the patina.

The patina. Working with foundry artisans, Jözef inspects and perfects the completed bronze. Next the patina, or color is applied. This is hand-applied by heating the bronze with a blowtorch to a desired temperature and applying a combination of chemicals. These chemicals work with the natural oxidation process. Brushing on various waxes while the bronze is still hot will lock-in the desired color. Jözef Sumichrast

"Meg", of Bedford & Coulter Studios heats the sculpture as the patina is applied.
"Meg", of Bedford & Coulter Studios heats the sculpture as the patina is applied.

Jozef's laborious casting process of a mold to make the wax, and a mold to make the bronze must be repeated for each casting. Some larger or intricate sculptures require numerous castings. Attention to detail such as internal reinforcement and mounting lugs help insure the sculptures permanency. Once the sculpture has been cast it attains a permanency, a kind of immorality that spans generations and centuries. Susan Snyder

"Swimmer" 2001© Jözef Sumichrast private collection Lake Forest, Illinois
"Swimmer" 2001© Jözef Sumichrast private collection Lake Forest, Illinois

 

back