Our Process
How We Make Magic in Metal
1. Original Sculpture
An artist sculpts a piece in the media of their choice, most often in clay, wax, or stone.
2. Enlargement
Sometimes an artist will sculpt a small piece they wish to be enlarged, or we might produce a larger version of an existing object. We use our state-of-the-art equipment to scan the piece and create a digital file that can be resized and milled to any dimensions.
3. Creating a Mold
After the sculpture, large or small, is complete, a mold is created using several thin layers of silicone rubber and a plaster housing.
4. Working the Wax
Hot liquid wax is painted or poured into the mold, allowed to cool and harden, and released from the mold. The wax duplicate is tooled by a foundry technician, who fixes any flaws and adds channels where the bronze will flow to form the piece.
5. Investing the Wax
A ceramic shell casing, nearly 1/2” thick, is built up around the wax by repeatedly dipping it in a slurry bath, then in a silica sand tank, and then allowing it to dry. Once the piece has been properly invested, it is heated in a kiln, where the wax melts and a void is left where the wax duplicate once was.
6. Casting
Bronze ingots are placed inside a graphite crucible heated to approximately 2000 degrees in a furnace. The molten metal is removed from the furnace, poured into the empty investment shells, and left to cool.
7. De-vesting & Cutoff
After the casting has cooled, the investment is removed using hammers, chisels, and sand blasting, and the bronze that filled the sprue channels is cut off.
8. Assembly
Now that the pieces are cast in metal, the foundry staff use welders and various power tools to repair any imperfections. On larger sculptures, multiple castings may be welded together and the seams chased back to look like the original piece of art.
6. Patina
Once the metal sculpture is finished, chemicals and heat are applied to the surface of the metal. The chemicals react with the bronze and oxidize in various colors and patterns, determined by the temperature of the metal and style of application. The patina is sealed to preserve the color.
10. Finishing
As a final step, the sculpture is often mounted to a stone, wood, or metal base. Pyrology can fabricate mounts in-house, or work with another vendor of your choice.
11. Delivery & Installation
Finished pieces, no matter how large, can be delivered and installed anywhere in the world. We will work with our clients’ facilities managers to ensure a piece is safely and properly installed.
12. Years of Enjoyment
Pieces cast in metal, and especially monuments and memorials, are meant to be enjoyed for many years. Even fully exposed to the elements, a piece will last indefinitely and can be periodically restored to look just like new.