Behind the Bronze: How Sculptures Are Made After the Clay

At Big Statues, we tend to only show the part of the sculpture process that we do in studio. That ends up primarily being sculpting from clay and foam. While we also dabble in rendering and molding, the majority of our time is spent sculpting. But this week, I got to witness the rest of the story, and it completely changed the way I view bronze sculpture.

I toured the foundry we partner with, Adonis Bronze in Alpine, Utah, and discovered how much more goes into the bronze sculpture process after the clay model is complete. From wax molds to molten metal and kilns, here’s a detailed look at what really happens after we finish sculpting.

Step 1: Creating the Silicone Mold

Once a clay statue is complete, the foundry begins by creating a detailed mold using RTV silicone. This soft, flexible material captures every curve, line, and texture of the original sculpture. It's crucial for translating the artistic expression into the final bronze.

To support the silicone, a hard mother mold made from casting plaster or fiberglass is applied. This rigid shell holds the silicone in place and ensures that it can be safely removed and reused during the next stages.

Step 2: Wax Casting

With the mold prepared, the next step is to create a wax replica of the sculpture. Hot wax is poured into the mold, rotated for even coverage, and left to cool. This forms a hollow wax version that is nearly identical to the clay original.

The wax pieces are then carefully trimmed, cleaned, and sometimes fused together if the sculpture is large or made in multiple parts. Matching these wax sections to the original design requires patience and precision for every connection to be seamless.

Step 3: Building the Ceramic Shell

Each wax piece is then repeatedly dipped into a ceramic slurry, dried, and layered multiple times. This creates a durable ceramic shell that will serve as the final mold for the molten bronze.

Once enough layers are built up, the ceramic mold is placed in a kiln and fired at high temperatures. This process melts out the wax from inside. It is known as the lost wax casting process, leaving behind a hollow cavity that’s ready for metal.

Step 4: Pouring the Bronze

This is the most dramatic moment in the bronze casting process. Molten bronze, heated to over 2,000°F, is carefully poured into the ceramic molds. As it fills the empty space once held by wax, the bronze begins to take shape.

After cooling, the ceramic shell is chipped away to reveal the rough bronze sculpture beneath. It’s always exciting to see the first glimpse of bronze. It’s like unearthing buried treasure.

Step 5: Welding and Surface Finishing

If the statue was cast in parts, those bronze pieces now need to be welded together. The seams are then ground down and retextured by hand to match the original surface of the sculpture. This is a critical step to ensure the final piece looks cohesive and natural. It not only takes metal working skill to complete this step, but also an artists eye and talent. 

From here, the foundry team works like sculptors all over again. They go through the refining, blending, and perfecting process until the bronze is ready for finishing.

Step 6: Applying the Patina

The final step is applying a patina, which gives bronze its iconic coloring. The patina ranges from deep browns and earthy greens to rich blues and blacks. This is done using a combination of heat, acids, and pigments, often applied with brushes or torches. Adonis Bronze often works with the sculptor to make sure the patina is what the artisit had in mind. 

Once the desired patina is achieved, the statue is sealed with wax or lacquer to protect it from weathering and oxidation, preserving its beauty for years to come.

Final Thoughts: A New Appreciation for Bronze Art

Before this tour, I thought I had a pretty good understanding of how statues were made. But seeing the full bronze sculpture process, from silicone molds to ceramic shells, from molten bronze to patina, gave me a whole new appreciation for the time, talent, and technical skill required to bring a statue to life.

At Big Statues, our role is to sculpt the story in clay, but thanks to incredible foundries like Adonis Bronze, that story gets cast permanently. Behind every bronze piece is a team of artists, welders, and craftsmen who make it happen.

Want to see what this looks like in real life? Check out our Instagram, Facebook, and Youtube to see the behind the scenes.

‍