Great Thinkers Throughout the World & Ages

Bronze Casting

A Portrait of Leonardo da Vinci by Jonathan Sherman. Jonathan’s oil paintings, drawings, and sculptures are housed in private and corporate collections throughout the United States, Europe, and Australia. Seven of his works of Art are in the private collection of Eijk and Rose-Marie van Otterloo, and recently he has been commissioned to create six bronze sculptures for the corporate collection of Maddox & Partners in Naples, Florida.

Bronze Casting

 

Bronze is a most precious sculptural medium due to its permanent nature, which allows castings to be displayed inside or out of doors. The Studio of Jonathan Sherman works with the foundry Sincere Metal Works based in Amesbury, Massachusetts, which utilizes the lost wax process for creating these works in bronze – a process that dates back a few thousand years. Below are images and accompanying text explaining the steps taken to create each sculpture.

 
The life size clay model, sculpted by the Artist, Jonathan Sherman.

1 — The life size clay model, sculpted by the Artist, Jonathan Sherman.

The first stage of casting in bronze is painting on layers of silicone over the clay model to create the initial mold.

2 — The first stage of casting in bronze is painting on layers of silicone over the clay model to create the initial mold.

Once the silicone mold is finished, a plaster mold is created around it for additional support.

3 — Once the silicone mold is finished, a plaster mold is created around it for additional support.

Hot wax is poured into the inside of the hollow mold. Once dry, the mold is removed revealing a hardened wax model.

4 — Hot wax is poured into the inside of the hollow mold. Once dry, the mold is removed revealing a hardened wax model.

The wax model is dipped in an initial layer of ceramic slurry, six more will follow to create a new mold 3/4 of an inch thick. (The wax model is then dipped into ceramic slurry upwards of 7 times allowed to dry in between layers, creating a hard she…

5 — The wax model is dipped in an initial layer of ceramic slurry, and left to dry. Six more layers will be applied, eventually creating a new mold, a hard shell, 3/4 inch thick.

Now the shell will be placed in a kiln in order to fuse the shell and melt out the wax, leaving an exact negative impression on the inside of the shell.

6 — Now the shell will be placed in a kiln in order to fuse the shell and melt out the wax, leaving an exact negative impression on the inside of the shell.

Molten bronze is poured into the now-hollow ceramic shell and assumes the exact shape of the wax model.

7 — Molten bronze is poured into the now-hollow ceramic shell and assumes the exact shape of the wax model.

Once the bronze has cooled, the sculpture is freed from its ceramic shell with a hammer.

8 — Once the bronze has cooled, the sculpture is freed from its ceramic shell with a hammer. After this, the bronze is cleaned and a patina is chosen and applied. The final step is to brush wax onto the hot sculpture.

 

9 — The finished sculpture.