Posted tagged ‘bronze casting’

throwback Thursday ~ bronze age edition

May 27, 2021

A long time ago, I took a few continuing education classes at the local community college. One of the classes was bronze casting, and I’d like to take that one again.

What you see above is the wax model of a bookend I eventually made. That’s Sisyphus, of course. The process is not that complex; it’s been used since ancient times, though I think the ancients had more talent than I do. You make your model out of wax, including the red parts that are channels for the molten bronze when the time comes. Then you dip it into a broth that is adhesive. After that you put your wet mold in a vat of crushed stone (like powder) to coat it. Repeat that a few dozen times until you have a shell of this crushed stone around your wax. Then (after the shell dries and hardens) you can pour the molten bronze into the shell. The wax melts instantly and evaporates. The bronze flows into the cavity left by the wax, and if you did your connections and proportions right, you will have a bronze replica of what you had molded in wax. (I also made an acorn the size of a baseball, and I got the proportions wrong with it, causing the heat of too much molten bronze in one place to “draw” itself away from the edge of the mold. Fun fact: all bronze statues of any size are hollow to prevent this from happening.)

Surprisingly, the bronze cools quickly enuf that you can start pounding on the stone shell with a hammer in about an hour. You break away the shell to reveal the bronze sculpture within. In a sculpture like mine, with a lot of Giacometti texture, you then must use tools to pick the shell out of the recesses. (This is tedious and painstaking, and after a while you say you’re done with that and any bits of crushed stone left on the sculpture are intentional.)

It had always been my plan to make a match for this bookend. And then I thought I should make a bunch more, using my round rocks for the boulders Sisyphus must push. But the class and the materials for creating just this one ended up costing about $100, and that was a little steep for a bookend.

Still, it’s a nice thing to say I created.