The production process flow of copper casting sculptures

Cast bronze sculptures and other cast sculptures begin with clay modeling, followed by the creation of a negative mold, and then a positive mold. Essentially, it's a material transformation process—from malleable clay to different materials like plaster and fiberglass for shaping, before being sent to a specialized foundry for final casting. Each cast bronze sculpture requires at least eight complex and meticulous processes, showcasing both traditional craftsmanship and the brilliance of modern precision casting technology. Let Sino-American Art & Design guide you through the standard production process of cast bronze sculptures.

First step: Creating small clay sculptures (Each product requires a clay sculpture prototype. Clay sculptures are re-creations made by sculptors after repeatedly pondering and refining the original design drafts. The quality of the clay sculpture's shape, whether it embodies the spirit, and whether it expresses the intention directly affect the quality of the future product. Therefore, excellent clay sculptures cannot be separated from excellent sculptors.)

Step Two: Applying clay to cover the sculpture's form. After applying the clay, use a wooden mallet to tamp it down and fill any gaps. After all the clay has been applied, the overall form undergoes continuous adjustments. The form may require rework and adjustments to the framework until satisfactory results are achieved; all of this must be done by a professional sculptor. From this stage onward, the sculpture must be frequently sprayed with water to prevent cracking. During breaks, it must be covered with plastic film to maintain moisture until the sculpture mold is completed.

Step 3: Making the clay sculpture prototype (The silicone mold that has been made again is already very complete and perfect. The heated and molten paraffin wax is injected into the silicone mold under pressure to create a wax blank, which is a replica of the actual shape of the product to be produced.)

Step 4: Once the large-scale sculpture is complete, notify the client to review the overall design and provide feedback or modifications. Continue to refine and adjust the details until the final shape is achieved. After completing the entire design, smooth the clay model using a scraper. The clay prototype needs to be refining against the prototype blank from Step 3. This is a crucial step, as it directly affects the final shape and surface finish of the product.

Step 5: Entering the casting stage, the clay sculpture is divided into sections using slicing tools, and then sprayed with soapy water for isolation and protection. Professional casting technicians prepare plaster slurry and apply it to cover the sculpture. The specific water ratio for the outer and inner layers of plaster slurry is controlled and completed by professionals. After the plaster hardens and dries, demolding begins. Before demolding, handles are fixed to the sections, and these handles are made of plaster caster.

Step 6: After demolding, remove any residual clay from the sectional molds. Then, carefully repair and polish the plaster mold. Finally, polish it with a copper mesh.

Step 7: Casting (The hollow ceramic shell from the previous process is placed in a sintering furnace and sintered at 1000℃-1150℃ depending on the alloy material. The molten copper is immediately cast into the ceramic shell. After cooling, the outer ceramic shell is broken and peeled off to reveal the rough copper product blank.)

Step 8: Finishing and processing of castings (sandblasting and cleaning of cast copper products, followed by grinding, heat treatment, shaping, machining, polishing and other post-processing).

Step 9: Surface treatment and protection (the desired effects for cast bronze surface treatment are usually divided into cold finishing and hot finishing. We will introduce the specific differences and characteristics of these finishing processes to you in future articles), followed by waxing and polishing.

Step 10: Apply oil and seal with wax

Applying oil and sealing with wax can help our bronze sculptures maintain their cutting-edge appearance for a long time.

Step 11: Art Director

Artistic supervision determines whether our bronze sculptures are accepted by the audience. Generally, only those with professional training or artistic talent can supervise the production.