Casting Bronze Sculpture
Bronze sculptures are typically created by in what is called the Lost Wax Process, which has not changed much since the time of the ancient Greeks. This process is labor intensive and time-consuming, involves many steps and a team effort to transform an idea into the beautiful bronze sculptures that are found at Greg Todd Studios.
The following description of the process provides a general overview of the process which actually takes months to accomplish.
1: Research and the Sketch
When working with a client, the first step is always to speak with them to learn what the image is to be and what the story is they want told. Additional research is done before a single sketch is created, particularly if Greg will be depicting a historical figure or event.
Some artists draw on paper, Greg prefers to work directly in three dimensions so once he has an idea of what the buyer is looking for and has gathered relevant photos and artifacts, Greg begins sketching possible compositions in clay.
“Sculpture is a lot like drawing in clay,” says Greg, “it really is drawing, but in three dimensions not two.”
During the sketching phase Greg will have a good idea of the details, including the position of any figures, what action is taking place, the environment that the people or animals are in, and any elements that are needed to tell the story. However, due to the small scale of the sketch, these details are not typically shown in the sketch.
At this stage making changes is quite easy. Sometimes the clay sketch will be reworked or the entire idea may evolve during the next meeting with the client.
2: Clay Sculpture Original
Greg will sometimes create a maquette, which is a small version of the final sculpture to more fully develop the composition or the flow of the piece. More frequently, once the initial clay sketch has been approved, Greg will move directly to the full-size clay sculpture.
During this phase some of the structure and design is resolved that are not visible in the drawing phase.
Some sculptures are small, designed to fit on a table. Other sculptures are life-sized or larger. No matter the scale of the piece, the clay is place on an armature which helps support the clay. The clay is built up to create the basic shape. The clay is then smoothed, appropriate textures added and final details put into place.
This involves working with photographs of the individual who is being sculpted and adding specific details that are important to the person who commissioned the work. For example, the Warren County War Memorial Committee provided Greg with personal items from the honored veteran to be incorporated into the monumental sculpture.
3: Creating the Molds and Wax.
Once the sculpture is completed in clay it will then have to be turned into bronze by creating molds and wax versions of the sculpture. Smaller sculptures may be cast in one piece while large sculptures are cast in many pieces and then put together again.
Rubber is painted on to the clay to create a mold of the original. Then plaster is applied to the mold so it retains its shape.
The mold is removed from the clay and is put back together again and then filled with melted wax. Small pieces will be solid wax while larger pieces will have a thick wax, but the inner core will remain hollow. Whatever is in wax will ultimately become bronze.
For sculptures that are made up of several molds, the waxes must be put together to recreate the sculpture. Joints and seams are “chased” and Greg can fine-tune the sculpture at this point, if desired, and sign the wax so his signature will be directly made in the bronze.
4: Spruing the Wax
Once the wax is complete to Greg’s specifications, wax rods called gates and sprues are attached. These rods will serve as roads or tunnels that the molten bronze will follow in order to create the sculpture.
5: Investing the Wax
The hard wax is dipped into a vat that coats it with a fine layer of silica sand, called the “shell.” It takes several coats to create a complete shell that is strong enough to withstand the process. This process cannot be rushed and it can take several weeks to create the shell.
6: Losing the Wax
The wax, now with its protective shell, is heated so the shell is dried out and the wax melts away. This is why the process is called “lost wax,” the melted wax leaves behind a hollow shell that will later be filled with bronze.
7: Pouring the Bronze
Bronze ingots are melted at roughly 2000 degrees Farenheit. The melted bronze is poured into the shells, which are in a sand pit that holds them vertical.
After the Pour, the bronze is cooled and the shell is removed with hammer and chisel and then by sandblasting. All the gates and sprues that were part of the original wax and are now bronze are removed.
9: Welding and Chasing
Most life-sized bronze sculptures are so large they must be cast in several pieces. Now these pieces are welded together.
Seams and minor imperfections will be chased away, just as they were during the wax process.
Most bronzes have some sort of patina applied once it is all welded and chased. Chemicals and heat are applied to the surface of the bronze. The process is a chemical reaction with the bronze, not merely painted on the surface, and it will last for the lifetime of the sculpture.
11: Bases and Installation
Many of Greg’s bronzes will now be placed on bases. Bases may be made from any material, most commonly wood or stone, or a combination of the two.
For life-sized and monumental bronze sculptures that are commissioned, Greg works with the buyer on how the base should be integrated into the work.
Greg works with the buyers and engineers to assure that the sculpture will be installed in a way that is safe for the work and the viewing public so they can enjoy their sculpture for generations to come.