A mold of the original sculpture is created using several thin layers of high quality silicon rubber and a fiberglass or plaster case.
Hot liquid casting wax is poured inside the rubber mold. Once cooled off, the mold is taken apart to reveal a wax replica of the original sculpture. At this point in time finishing touches are made to the wax by a foundry technician using modeling tools and any flaws in the wax from the process can be removed.
A network of wax rods or sprues and a wax cups or attached to the wax positive. This complex procedure will provide the feeding system through which the molten metal will travel later in the process to achieve the casting.
A slurry mixture and varying grits of sand is applied in successive coats. Reinforcement of critical stress points is necessary. It’s a slow process because each coat has to dry before another one is applied.
The complete wax structure which is invested in ceramic, is then heated in a kiln until the wax runs out and all free moisture is removed. The ceramic shell is then filled with molten bronze.
After pouring, the ceramic shell is removed revealing the cast bronze. At this stage all that was once wax, is now bronze, and so the feeder or sprue system is also removed , leaving just the casting which will now be ready for metal finishing.
The final finishing of the sculpture is accomplished with the help of pneumatic and electrical rotary tools. An expert welder uses welding rods to weld any seams, imperfections, or additions on the finished sculpture.