The artist starts by modeling a piece from wax or another material.

Once this has been achieved, the artist brings the piece to the “fonderie d’art”, which is the workshop where her piece will be transformed into the finished bronze sculpture. (here, the Foundry of the Gour in Charbonnières-lès-Vieilles, Puy-de-Dôme)

Mould making
A mould is made of the original sculpture. Regarding the complexity of the artwork, most moulds are at least made of two pieces, and a shim with keys is placed between the two halves during construction so that the mould can be put back together accurately. Then, we put in place the hole for pouring the bronze into the mold.

Most moulds of small sculptures are made from plaster, but can also be made of fiberglass or other materials. To preserve the fine details on the original artwork’s surface, there is usually an inner mould made of latex, vinyl, or silicone, which is supported by the plaster part of the mould.

Removal from the mold
We see here the impression of the piece left inside the mold.

The Wax
Once the plaster and latex mould is finished, molten wax is poured into it and swished around until an even coating, usually about 1/8 inch thick, covers the inner surface of the mould. This is repeated until the desired thickness is reached. The wax should be soft enough to shape and yet hard enough to stay put and hold detail. The wax copy of the artwork is removed from the mould.

The piece is removed from the mould, wax smudges and mistakes are cleaned, the small bubbles of air are recapped: this is the retouching of the wax.

Preparation before the pouring
Tubes are then attached to the wax sculpture allowing the air to exit and another for introducing the liquid bronze.

The Making of a mould is in two pieces: plaster and fire-clay, which is going to accept the heat and avoid explosion during the pouring process.

Drying and cooking of the mould: the wax melts and is evacuated.

Pouring the bronze

The shell is reheated in the kiln at about 1200°C to harden the patches, then placed cup-upwards into a tub filled with sand. Bronze is melted in a crucible inside a furnace, then poured carefully into the shell. If the shell were not hot, the temperature difference would shatter it. The bronze-filled shells are allowed to cool. After cooling, the moules are broken and the piece appears: this is called the décochage (to punch).

The tubes that were attached before the pouring are now sawed off and the piece is cleaned.

The Carving

The bronze copies are worked until the telltale signs of casting are removed, and the sculptures again look like the original artwork. Pits left by air bubbles in the molten bronze are filled, and the stubs from the sawed off tubes are filed down and polished. Now the bronze is ready to be given a finished sheen.

The Finished Sheen
The bronze is coloured by using heat and different metallic oxides. Each foundry selfishly keeps the secret of colours and finishing techniques, which really makes its reputation. Regarding law, bronze edition is limited to eight original numbered pieces. Four épreuves d’artistes are added. Originally, these four pieces were given to the family and Institutions ; today, most of the artists sell them.