One of the best parts of attending a workshop near the artist's home is the ability to visit her favorite foundry. We had the immense privilege of a personal tour of Laran Bronze with Larry Welker, one of the owners. They are established in a wonderful, old building in Chester, PA. All of the employees are artists and wonderful people. After going through the myriad of steps it takes to produce a bronze, you will understand why they are so expensive. And every step along the way requires skilled labor. I will try to recap what I learned, but forgive me if I leave something out.
After the clay sculpture arrives, it is gradually covered with multiple layers in a kind of rubber substance. This will capture all of the detail in the original clay sculpture. Above you can see how it is brushed on. On the sculpture below it was airbrushed on and drips off, repeated multiple times.
The rubber mold is than covered in a plaster-like casing, which is then cut apart into multiple pieces. The pieces are bolted together to receive the wax. The wax is poured in and swished around on the inside and then the excess is spilled back out on the floor to be reused after it is cooled. The purpose is to create a hollow wax version of the sculpture. A solid-cast piece in bronze would be too heavy and expensive, so the wax mimics the end result they want to achieve in bronze.
I believe this is Allen showing us how the vents and sprues are created in the wax casting. There are pieces cut out that will be cast separately that allow him to vent to the inside, leaving less clean-up work. If the original clay was cut into pieces for ease of mold-making, it is often reassembled at this stage. Any pieces not reassembled at this stage, will need to be reassembled in metal.
Once the wax sculpture is prepared, a specially formulated casing is created around the wax. First it is dipped in liquid, then in sand. Because of the hollow nature of the piece, the sand is blown and the sculpture dipped into it. This allows for an even coating. It takes four hours to cure, then the process is repeated as many as a dozen times or more.
This is an example of the finished mold with the addition of some chicken wire in later coatings to add strength. The wax sculpture is inside this shell. I have no idea what it is.
The next step is to heat the wax to something like 1400 degrees in less than a minute. Larry explained that you have to cause the wax to melt before it can expand or else it will crack the casing and it will not be able to hold the molten metal.
Once the wax is melted away, which they recycle by the way, the outside casing is ready to have the molten metal pored in. Above Larry is showing us a brick of bronze, which has a special blend to allow for long-term outside exposure. They also do aluminum castings.
The final step is to add the patina, which is brushed on, then blow-torched to set. The patina reacts chemically with the metal.
I am just blown away by the skill that the people of Laran Bronze have to recreate sculptures. And if that weren't enough, they also offer 3D scanning and enlarging/shrinking. Above Chris is digitally capturing the sculpture.
After they have the image scanned, they can recreate it larger or smaller in foam with this machine that cuts it precisely. Some artists will then sculpt a thin layer of clay over it, but it is possible to use a high density foam that can then be painted as the finished product. Amazing.
But that wasn't all we did today, Kathy brought in a real skull and a cross-section of a real forelimb. You don't get to see things like that everyday!
There wasn't much time for sculpting today, but this is where I was this morning before our trek out. I have been playing with the headset and the stride, going back and forth. After this evening I am pretty content with the leg placement, if I can just keep them from moving! Hard to believe tomorrow is the last day...
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