How a Bronze sculpture of a Horse is made: The Lost Wax Bronze Casting Process
Creating a Custom Bronze Horse Statue:
The slide show on this page takes us through the process of creating a finished bronze horse statue from a clay model. This bronze horse sculpture of a running thoroughbred stallion was first modeled in clay.
Next, the clay version of the bronze horse is coated with liquid rubber & the rubber is allowed to set up. Subsequent layers of rubber are added after each coat dries. After the third coat of rubber, aluminum shims are added to allow the mold to be opened and the clay horse sculpture removed from the finished rubber mold.
Mesh fabric is embedded in the rubber after the fourth coat of rubber to give the mold strength, then more coats of rubber are added to finish the rubber part of the mold over the horse sculpture. Paper shims are added to divide the pieces of the fiberglass Mother Mold. The fiberglass "mother mold" is then built around the rubber mold
The finished mold is removed from the clay sculpture and reassembled.
Then, wax is poured into the mold and the hollow wax sculpture is cut into pieces to allow it to make a good casting.
A bronze sculpture must be hollow in order for the bronze to cast well. The walls of the wax piece must be relatively thin, 1/4 inch or less. In bronze casting, a thin bronze is a good bronze because there will be less shrinkage or distortion in the sculpture. A good bronze sculpture casting that is thin reproduces the fine details of the artists original work without distortion. The wax pieces are then attached to a wax cup with wax "straws" or sprews.
The horse sculpture head is a hollow wax copy of the original clay model which has been attached to a wax cup with "sprews" or "gates" which are solid wax straws. The wax is then coated in slurry and covered with sand.
The first layers of sand are a fine grit that picks up all of the detail of the sculpture, even down to the artists fingerprints that were left on the piece. Then the later layers are a coarse sand to add strength to the shell.
Successive layers of slurry and sand begin to build a ceramic or "rock" shell around the wax.
The "rock" or ceramic shell that coats the wax sculpture is then placed in a burnout furnace where the wax is flash melted out and the shell is heated to about 1800 degrees.
At the same time, bronze ingots are heated in the crucible furnace until they are liquid and also about 1800 degrees. The shell is then pulled out of the burnout furnace and placed in a sand filled cart which is wheeled under the crucible where bronze has been heated until it is molten. Then the liquid bronze is then poured into the shell.
The ceramic shell filled with molten bronze is then set aside to cool. When it has cooled and the metal is once again solid, the shell is broken off to reveal the bronze sculpture.
The bronze sculpture pieces are then sand blasted to clean them, and any parts that were cut off to cause the piece to cast better are welded back on. The welds on the bronze statue are ground down and then re-textured in a process called "metal chasing". A final sandblast and check are then done on the bronze sculpture to prepare it for the patina or color. The raw bronze horse sculpture is sandblasted and ready for patina. A bronze statue, if left in this raw state will naturally go darker and darker, eventually becoming nearly black or, if exposed to water, green due the the high copper content of the bronze metal.
The finished bronze horse statue after patina (color) is then applied by the use of chemicals and heat processes to change the color of the metal, The finish is then sealed with a coat of hot wax, and the piece is mounted on a beautiful walnut wood base.
Horse sculptures and bronze statues created through the lost wax casting method. Each bronze horse sculpture is hand poured in wax, and taken through the lost wax casting process by skilled artisans. There are many steps and a number of skilled foundry workers involved in hand finishing each bronze horse statue.