Jim Beach is one of AMPS most senior members. His sight is now impaired - as he described in the article about his film on the subject: Hemianapsia. This film was a Ten Best winner at NAMMA 2009.

TRADING WAX FOR GOLD

by Jim Beach

NEVER TOO OLD

Still from 'Lost Wax'. With my 91st birthday and the October first deadline for the fall movie contests imminent; I decided to make one more movie. I couldn't get out and shoot new scenes, but I could still edit. So, I pulled up a movie that I made in 1992. It was a documentary I had made for teaching a class in jewelry making. It was way too long, and detailed, for our type of movie contests. I decided to rename it, shorten it, and re-edit it with a few new scenes. I named it, Trading Wax for Gold. *

The original movie, Lost Wax, was made entirely by me, using a tripod and a remote control. One scene used two cameras and my wife turned one camera on an off to show the scene from two views. It was recorded on Super VHS-C tape. After 17 years the tape had no drop-outs but I boosted the color saturation and adjusted the contrast a bit. I hope, that those who see it enjoy it, and learn a bit about the ancient art of lost wax casting.

After re-editing this movie, I decided, "Hey! maybe I can still do some of that." I can't see well enough to do real fine jewelry work but maybe I can make a silver handle for my favorite cane. My hands are still steady and my fingers work well. Such a project shouldn't require really close work. Then I decided, why not make a video record as I go. Maybe I'll edit it for the 2010 contests.

It turned out to be a much bigger project than I anticipated. But then they often do.

Still from 'Lost Wax'. Still from 'Trading Wax for Gold'. The casting will be bigger than any I have made before, and it has to be in two pieces to fit my centrifugal casting machine. Also it will be a hollow casting which requires new procedures, new to me anyway. Once the casting process is underway the wax models, and hours of work, are lost forever. That's why it's called lost wax. The first time I will know if it's a success or failure, will be after the molten metal is forced into the mold, cooled and then broken out of the mold. I'm betting on success and I'm making good progress.

I'm recording video scenes each step of the way. Hopefully I will be able to, not only end up with a sterling silver handle for my cane, but scenes for a new movie to edit for the 2010 movie contests. I have a little Canon camcorder that is supposed to record HD and 16x9 format, but I can't read the tiny labels and manipulate the controls, and my editing gear doesn't do HD. So I decided to use common sense and stick to my trusty Sony TRV-900 three chip camcorder, and a 4x3 format.

Never too old to learn, but smart enough to stick with what works best for me.

[Webmaster: Jim has made the new film - read about it here.]

*Lost Wax Process: Casting jewelry and small parts

Essentially a wax shape is covered in mold material which sets hard. This is heated so that the wax runs out and then molten metal can be poured in. The metal cools and sets in the pattern of the original wax shape.

The methods used for small parts and jewelry vary a bit from those used for sculpture.

A wax is obtained, either from injection into a rubber mold, or it is custom-made in wax. Occasionally, a custom-made wax might be molded in rubber first as insurance against the loss of the unique wax and related labor costs incurred in carving it. The wax or waxes are sprued and fused onto a rubber base, called a "sprue base".

Then a metal flask, which resembles a short length of steel pipe that ranges roughly from 1.5 to six inches tall and wide, is put over the sprue base and the waxes.

Most sprue bases have a circular rim which grips the standard-sized flask, holding it in place. Investment (refractory plaster) is mixed and poured into the flask, filling it. It hardens, then is burned out. Casting is usually done straight from the kiln either by centrifugal casting or vacuum casting.

The lost-wax process can be used with any material that can burn, melt, or evaporate to leave a mold cavity.

Picture of mold and cast from Wikipedia.

On the left is an example of a rubber mold, often used in the lost-wax process, and on the right is the finished bronze sculpture.
(Sculpture Holocaust by David Ascalon).

This edited extract from Wikipedia is used under the Creative Commons Attribution/Share Alike licence. For the full original article click here.