Molding 24K Gold from Integrated Circuits: A Guide for Hobbyists

Question
Hello there Sir...
I am a hobbyist, extracting gold wires from integrated circuits. I have collected a good amount of gold and i want to mold it in a shape that i desire. This gold is 24k pure, it is so soft. Can you please suggest a way on how to make a mold that is easy to make. Thanks.


Answer
Butch, thanks for this question.  What I say is based from my experience in working precious metals.

First of all, I can think of no practical way to form the gold by pressure alone, hammering and such or a mold which could be used for the process.  I suppose it is possible to intertwine the wires and then forge to some shape and it might hold together with nothing but a mechanical overlap to secure the wires together.

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I recommend a mold made of plaster. Plaster of Paris will work but the "investment plaster" used by jewelers for lost wax casting is better since it will stand heat much more effectively. A local jeweler who does casting may supply you a small amount for one mold.

Make the design in wax, molded or carved or melted to form. Make the design with a flat back and the design on one side essentially.  The plaster is mixed and placed into a shallow pan. The wax model is pushed into the still liquid plaster and held there with some object across the back of the wax until the plaster hardens.  The idea is to have the back of the wax design flush with the surface of the plaster.  After about 45 minutes to an hour, gently remove the wax model.  A duplicate reverse shape will remain in the plaster.

The idea now is to melt the gold and pour it into the mold cavity. The plaster should be totally dry and I cannot state that strongly enough.  Heat in a oven gently raising the temp to nearly 500 F to be certain it is dry. (In lost wax casting, the molds are heated to 1250 F or so and casting is done at 1000 F or slightly cooler.)

While still hot, remove the plaster mold, melt the gold and pout into the mold cavity.  Place a flat fireproof surface on the gold to level it into the cavity.  A jewelers charcoal block works well or a piece of heat proof tile will work as well.  Allow the gold to cool and solidify.  Remove the gold and it will have the form of the design from the plaster mold.  Now, the work is to finish as desired.

Butch, that is about as basic a mold as you can get.  Best wishes with the project.

God Bless and Peace.  Thomas.  July 17, 2008  7:16pm