Since the majority of our cast sculpture awards (both custom and stock) are created from bronze and pewter, we often get questions about the differences between these two metals. We recently posted a blog that outlines the major differences. However, many of our clients are also interested in learning more details about how awards created using these metals are actually produced, so we wanted to recap the production process surrounding our pewter awards.
The production process for pewter sculpture awards is, in many respects, the same as that for bronze sculpture awards. In both cases, designs start with a model, a mold is made around the model, and melted (molten) metal is poured into the mold’s cavity, which is in the shape of the original model. There are, however, a few significant differences based on the differing properties of each metal.
Pewter is a softer, more malleable metal than bronze, and, as such, it melts at much lower temperatures (approximately 500 degF versus 2,200 degF for bronze). This results in pewter having a simpler casting process than bronze, although both require a high degree of skill and experience.
The steps required to create a pewter sculpture award are as follows:
- Step 1: Model Creation: The first stage in creating a pewter sculpture award is to create a model in the exact shape of the desired final award. Most commonly, these models are created using wax or clay. And, in most cases, these are hand-sculpted, although with the advent and proliferation of 3D printers, some models are now created using this technology.
- Step 2: Mold Creation: The second state in the pewter casting process is to create a mold around the original model. This is created by applying multiple coats of silicon rubber to the model. Once the target thickness is achieved, and the rubber has hardened, the mold is sectioned and the model is removed. What exists now is an open cavity in the shape of the original model.
- Step 3: Pewter Pour: The first two steps are “one time” steps – they don’t need to be repeated each time a new pewter sculpture is created. Step 3, the Pewter Pour, is the beginning step in producing (casting) all subsequent pewter sculptures based on that specific sculpture design. In this step, pewter is heated until it achieves a liquid consistency. Once it is in liquid form, it is poured into the rubber mold cavity. Sometimes during this step, the mold is attached to a spin-casting machine that rotates the mold as the molten pewter is poured into it. This centrifugal force helps ensure that the molten pewter completely fills all of the cavities of the mold.
- Step 4: Chasing: Once the pewter has cooled and hardened, it is removed from the rubber mold. Pewter residue attached to the sculpture resulting from the pour is cut off the sculpture. It is then sand-lasted to remove any remaining particles. Finally, special power tools are used to remove any remaining imperfections and smooth out the surface of the pewter sculpture.
- Step 5: Finishing / Plating: In this step, the pewter sculpture award is either buffed to a natural, satiny finish, or plated with another metal (usually gold or silver).
- Step 6: Mounting: The vast majority of our pewter sculpture awards are mounted to a base, so, in this step, the pewter is attached to a base (usually marble or wood). The pewter sculpture is now ready to be presented as a unique, handcrafted sculpture award!