Here’s the first little nude bronze I ever cast right after breaking it free from its sand mold following a bronze pour in Moncure, NC last spring.
Kevin Eichner teaches this class through Central Carolina Community College that covers the basics of bronze.
It’s a lot of work.
We started with wax models of our piece, then added what Kevin called a pouring system, or sometimes it might be referred to as sprues made of bendable wax sticks.
We mixed bags of sand and a two part epoxy in what looked like a cement mixer to create our sand mold material. We added large chains and other heavy metal items which we kept careful count of to the cement mixer to help break up any lumps. It was pretty smelly and dusty. We built wooden forms to suit the size of our pieces. Then we carefully packed our wax models into the sand mold material.
You can see on the tops of the remaining molds sitting around me that there is a large hole for pouring in the bronze and several small holes for the bronze to ooze out of, to purge all the air pockets. When the bronze contracts as it cools, metal reserved inside of the pouring system is drawn into the cast art. This prevents pitting in the finished work.
The leftover bronze is made into ingots and used again for another pour. The piece has to be cleaned up. I am using a grinder here to remove sprues. You can polish and use bowling floor wax or apply a patina.
The leather coverings I have on over my calves and shoes are part of the protective gear for pouring bronze. We wore leather overcoats, aprons, leggings, hair pulled back and a face shield.