Imagine being able to invest, burn-out and cast platinum in less than three hours. Using conventional investments this process will require anywhere from six to 24 hours to achieve.

The investment used for this method is a hybrid from the dental industry, and has been adapted for use with platinum. The introduction of high-speed dental investments to the jewelry industry led to the development of this casting process It is fast and easy to do and that makes this material ideal for the small shop. A wax model is being invested, and in as little as two to three hours, one can accomplish anything from simple to complex castings, bi-metal castings and even stone-in-place casting in platinum. Even the de-vesting i.e removal of investment material after casting, is now safer to do. Using newly developed acid substitutes rather than Hydrofluoric acid is an additional safety feature. The casting is done using a vertical platinum casting machine, as well as an enclosed dental casting machine This paper will explain a no-nonsense method to cast platinum in the small shop. Castings are being done without the use of a metal flask.

The torch set-up and fuel gas options are explained in detail. This includes safety information. For more detailed information please consult the original paper.The most efficient way to melt platinum with a torch is a Hydrogen flame, pushed by Oxygen. The fuel is Carbon free, and fast. The high BTU created by the proper Hydrogen/Oxygen flame will melt the platinum in seconds

Using the high speed dental investment, the powder is mixed with the binder in a precisely measured amount. One can use a kitchen blender, or a sophisticated vacuum mixing machine for this process. Any trapped air will be removed and the investment mix is being poured over the wax models , filling the plastic flask.. After set-up, the plastic flask is being removed from the form and the form is being placed into a pre-heated kiln at about 1250 F for burn-out. After burn-out, the flask is being placed into the casting machine, the platinum is melted and the centrifugal force shoots the liquid platinum into the form. The platinum will now take on the shape of the wax model, which made the impression inside the form. After casting, the form will be broken and the cast piece removed for further manufacturing steps.

In later experiments, diamonds, rubies and sapphires were installed in wax models and successfully cast in platinum. For more detailed information, consult the original paper.

A very special thank you to Marc Robinson of PM WEST in Los Angeles, who took on the task to daily cast platinum testing seven types of high speed investment. It was Marcs willingness to listen to my suggestions and then do it better than anyone else could.

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High Speed Platinum Casting for the Small Shop
Jurgen J. Maerz
Director of Technical Education
Platinum Guild International USA

This is an abbreviated version of the original work. For full technical details, please consult the original paper.