What is the Bronzing Process?

More appropriately called the "Lost Wax" process, here are the eleven steps used to create my sculptures.*

  1. An artist's completed sculpture is taken to the foundry, bid, photographed, and measured.

  2. It is then cut up so that the mold will pick up the most details and pour well in wax and metal. The mold is made of silicone rubber then covered with a thick plaster out mold.

  3. Several (4) coats of wax are poured into the mold. Each coat being allowed to cool and then the mold is removed.

  4. Wax chasers clean, repair, smooth, replace detail, cut windows, etc. to prepare the wax for the rest of the process.

  5. The wax goes to be sprued which is attaching the waxes to a cup with sprue wax to make the channels for the metal to reach all parts of the piece.

  6. Eight coats of slurry are then applied with 24 hours drying time between each coat to make a thick ceramic shell surrounding the wax.

  7. These shells are then put in a burn out oven and heated to 1,500 degrees to melt out the wax, leaving a cavity for the bronze.

  8. The hot shells go into the foundry room and are heated from 1,900 to 2,100 degrees then filled with molten bronze.

  9. Sledge and jack hammers are used to carefully chip the shell off so that the bronze can be sandblasted.

  10. Metal toolers then begin welding the pieces back together, aligning, buffing, grinding, and repairing detail and texture until the sculpture looks as if it were cast in one piece.

  11. The final process is patina. This is where color is put on with heat and chemicals then hot waxed to seal and stop any chemical action.

* By David Manuel, "Bronze,"
Manuel Museum Workshop and Foundry Tour