Preparing Wax Rings for Casting in Sterling Silver
I was looking through some older pictures when I ran across these. They were taken when I was preparing for an art show in October 2007. In these pictures there are approximately 30 rings that will be cast in sterling silver.
I plan to write another posting that offers more in depth information on the casting process. Until then I’ll give you a brief overview.
The casting process begins with a wax model of the piece(s) of jewelry you want cast. All wax pieces are attached to a wax base with short wax wires called sprues. A metal cylinder is then fitted securely to the base. You want at least one inch between the cylinder walls and the waxes. The same distance is used for the top of the waxes to the top of the cylinder.
Next a special plaster of paris mixture called investment is poured into the cylinder. The mold is now cured. Then the mold is placed into an oven to burn out the wax and any wax residue. This takes from 6 to 8 hours. At this time you can take the mold from the oven and pour molten silver (or gold) into the mold. Let it cool for a few minutes, then plunge the mold into water. The investment will dissolve and you will be left with a silver image of your waxes.
In the picture on the left (click for a larger image) I am adding short wax sprues to the wax ring. You can see one on the table top. The sprues are attached to the edge of the ring or just inside so they do not interfere with the design of the ring.
The center picture above shows the wax ring being attached to the main sprue. The rings are attached at an angle that allows the molten silver to flow down into the cavity of the mold. The cavity is created when the wax is burned out of the mold. This is the tenth ring added to this mold.
The right most picture above shows the top of the main sprue being trimmed. This extra wax is unneeded and also reduces the amount of silver needed to pour the rings.
The picture on the left above shows all three wax trees. The next step is to dip them in a solution that helps prevent air bubbles when the investment is added.
The center picture above shows the silver rings after the investment has been mostly cleaned off. Not quite the shiny silver one would expect.
And lastly the picture on the right shows some of the rings, polished and on display. A couple of those rings were made into a set of sterling silver wedding rings for some of our special friends. Her ring is set with three rubies.
