Lost wax casting is a technology that has been used for thousands of years. I use it to make jewelry and small buckles that I sell at both my Etsy store, and my walk-in store, Dragon’s Treasure, in Fresno, California.
To make something with lost wax casting, you must first make a wax model. This can be as simple as a textured oval or as complex as a three dimensional squid or roller skate.
To do this, you will need special wax, some simple tools, and, possibly, a heat source such as a candle or alcohol lamp. Some people like to get a hard wax and carve it, while others like a very soft wax they can shape with their fingers. I use an in-between method. I use an inexpensive alcohol lamp to heat sheets or wires of wax until they are malleable.
I make a basic shape and then attach other bits of wax, using the alcohol lamp to partially melt them so they will hold together. I use wax carving tools that are like old fashioned dental tools to help shape and to add texture and detail.
Once I have made a wax model that I like, I put it in a heavy gauge metal flask. The flask is basically a very sturdy tube with a removable end cap. Once the wax is secured inside I pour in casting investment, which is a kind of plaster. When the plaster hardens I put the flask into a kiln so that the heat will melt out all the wax. When the wax is gone, there is a negative image of my model left in the plaster.
I place the flask that has the negative image of my model surrounded by plaster on one end of the arm of a spring driven centrifuge casting machine. I put a crucible filled with bits of sterling silver (called casting grain) on the other end of the casting machine arm. Next, I use an oxyacetylene torch to melt the sterling silver, then I let loose the catch on the spring driven centrifuge arm. I have to leap out of the way in case something comes loose that shouldn’t, which could throw molten metal all over the room. I must admit that I have been burned a few times over the years.
After allowing a little time for the metal to cool and harden, I take the flask and put it in a bucket of water to dissolve the plaster. I now have a rough sterling silver casting of my wax model.
Once I have the rough casting, I use a flex shaft and a tumbler to turn my rough casting into a beautiful, shining sterling silver pendant.
When people tell me they would like to learn how to make things using lost wax casting, I tell them to look for classes at their local community colleges or adult schools. This way they can practice with all the different equipment to see what tools they like before they spend their money on it. Wax, alcohol lamps, wax carving tools, and even tumblers are not expensive, but kilns, a centrifuge casting machine, and flex shafts can add up. It’s good to try them out first.
I buy a lot of my tools and equipment either online or from Rio Grande in Albuquerque, New Mexico.
Spickard was an exhibiter at the Fresno Mini Maker Faire.