How We Produce Your Sculpture Awards
We receive many questions about how our recognition awards are created. The process required to create our achievement awards is different for each type of award: bronze sculpture awards, pewter sculpture awards, crystal awards, glass awards, custom-cut metal awards, etc. Each of these processes is unique and fascinating, and requires the work of highly skilled artisans with many years of experience. Understanding the many steps involved in each of these processes adds to the appreciation of these awards, and helps our customer understand the time, effort, skill and artistic ability required to create them – these are not simple products “stamped out” in a factory overseas.
How'd They Do That?
Outlined below are the production processes for our bronze and pewter sculpture awards, which are generally the most complicated and lengthy processes. Over time, we will add to this list and describe the processes for our other types of awards.
Bronze Sculpture Awards
Our bronze sculpture awards are created using the “lost wax” casting process. This process has been in use for thousands of years with very little change. It is a very lengthy, labor-intensive process that requires skilled artisans with many, many years of experience. Achieving high-quality castings is very difficult, and is truly part science and part art. Each sculpture is individually crafted; thus, each piece is “one of a kind” – no two pieces are identical. The idiosyncrasies of each sculpture add to their beauty and uniqueness, and are part of what establishes them as true works of art.
Step 1: Create a Model
The first step in creating a new bronze sculpture award is to develop a model. Models can be created out of a variety of materials, and the size, complexity, and design of the sculpture all play a role in determining the optimal material to use for the model. The most common materials used for our models are clay and wax, although harder materials, such as high-density Styrofoam, can be used as well.
Step 2: Create a Mold
Once the model has been finalized, a mold is created. Molds are created by coating the model with silicon rubber. Multiple coats are applied to achieve the desired thickness. Once this thickness is achieved, and the rubber hardens, a harder plaster-like shell is often applied to the outside of the mold to protect it. If a sculpture award is large enough, the mold may need to be made in multiple pieces. Once these steps are complete, the mold is ready for the next step of the production process.
Step 3: Create a Wax Replica
Steps 1 (model creation) and 2 (mold creation) are “one-time” processes. Once these are initially completed, Step 3 (wax replica creation) is where all subsequent productions of the sculpture award will begin. In this step, wax is heated until it achieves a liquid-like consistency, and then the wax is poured into the cavity of the mold. Depending on the size of the sculpture, wax may be poured to form a solid wax replica; in the vast majority of cases, however, successive coats will be poured in order to form a hollow wax replica. Once the wax pouring is complete, and the wax has fully cooled and hardened, the wax replica is removed from the mold. Any imperfections in the wax replica are corrected (“wax chasing”), and the replica is now ready for the next step.
Step 4: Prepare the Wax Replica for Casting (Spruing)
The wax replica must now be prepared to create channels for the molten (melted) bronze that will eventually be poured into its space. A “pouring cup” is attached to one end of the wax replica using a set of long wax “spue lines” that will serve as conduits for the molten bronze to be poured into the sculpture. In addition, some of these sprue lines are attached in order to release air that could be trapped when the bronze is poured, creating imperfections in the bronze sculpture. Knowing where to attach these lines is part science and part art, and a very important step in the process.
Step 5: Coat the Wax with a Ceramic Shell (Investment)
The “prepared” wax replicas, including pour cup and sprues, is then dipped in a heat-resistant liquid, called “slurry”, and then a heat-resistant sand, called “stucco”. This process continues across multiple coats, and each coat must fully dry before the next coat is applied. Once the coats are complete, and the material fully dries, it becomes a hard ceramic shell, often called “investment”.
Step 6: Burn Out the Wax (Burnout)
After the ceramic shell is completely dry and hardened, it is inverted (cup and lines pointing downward) and placed in a kiln at approximately 1,800 degrees. The heat in the kiln serves two purposes: a) it further hardens the investment shell, and b) the wax inside the shell melts and drains out of the shell, leaving a cavity in the shell in the exact shaped of the original model. This is where the term “lost wax” process comes from,
Step 7: Pour the Bronze (Pouring)
The now-empty ceramic shell is now placed in a sand pit with the pouring cup facing up. Bronze ingots are placed in a crucible and heated in a furnace to a temperature of approximately 2,200 degrees – at this temperature, the bronze melts into a liquid form. Next, the molten bronze is poured into the empty cavity in the ceramic shell (into the pouring cup, and flowing down through the spue lines). The bronze is then allowed to cool and harden. Once the bronze has fully hardened, the ceramic shell is broken away from the bronze sculpture award (“Release”), which is now in the shape of the original model.
Step 8: Finish the Bronze (Finishing / Chasing)
A number of steps are required to “finish” the bronze sculpture award. First, the sprue lines are cut off. Next the sculpture is sand-blasted to remove any other unintended particles left over from the bronze pour. Following that, any parts that were separately cast are welded back together. Finally, the bronze sculpture is ground (similar to sanding) using power tools and progressively finer grades of sandpaper-like material. This step, called “chasing”, requires many hours of physical, labor-intensive work.
Step 9: Polish and/or Patina the Bronze
At this stage, the bronze sculpture award is either polished to a shiny finish (high-polished), or colored by applying (via brush or spray) chemicals that oxidize the bronze. This coloring is called “patina”. Different chemicals and application techniques can create different colors and surface patterns. This patina process is a true form of art in and of itself.
Step 10: Mount the Bronze Sculpture Award on a Base
The final step is to mount the completed bronze sculpture award on a base. These bases are usually marble or wood, but can be created in other materials as well. The bases generally feature custom engraving – either on the base itself, or via an engraved plate attached to the base. More information on these award bases can be found at:
A video on the lost wax production process can be viewed at: "The Lost Wax Bronze Sculpture Casting Process".
Pewter Sculpture Awards
The production process for pewter sculpture awards share many of the same steps as the process for bronze sculpture awards. However, there are some key differences in the properties of these metals that result in some important process deviations. Pewter is a “softer” metal than bronze, and melts at much lower temperatures. The net result of this is that pewter casting requires fewer steps than bronze casting. Here are the main differences in the pewter sculpture production process versus the bronze process described above:
1. Melted pewter can be directly poured into the rubber mold. Thus, Steps 3 through 6 above are eliminated.
2. Since pewter is a softer, less dense metal than bronze, it melts at a lower temperature. The temperature required to melt pewter in the Pouring step (Step 7 above) is approximately 500 degrees.
3. Pewter molds are often attached to spin-casting machines that spin the mold while the molten pewter is poured into the mold cavity. This centrifugal force helps ensure that the molten pewter completely fills all of the cavities of the mold.
4. Since pewter is a softer metal than bronze, the time and effort required to chase the metal after it is poured (Step 8 above) is less than that required of bronze. It is still a task that requires a great deal of experience and skill, however.
5. The finishing techniques and options for our pewter sculpture awards are different than those associated with our bronze awards. (Step 9 above). Pewter sculptures can either be buffed to a natural, satiny, brushed pewter finish, or plated with another material, such as gold, silver or bronze. Pewter is sometimes painted as well to achieve a specific color.
Like bronze sculpture awards, our pewter sculptures are hand-crafted one piece at a time. Thus, no two pieces are identical. Every sculpture is unique and has it own distinctive “personality”.
A video on the pewter casting process can be viewed at: "Casting Pewter".