Firing metal clay at the appropriate settings in a programmable kiln should produce excellent results.
Small kilns developed especially for firing precious clay are preferable to larger kilns which may suffer temperature fluctuations which can over or under fire the clay.
Programmable kilns are very handy if you wish to include glass, fused glass, dichroic glass or glass enamels in your precious metal clay jewelry designs.
Using The Kiln
You will require some form of kiln furniture such as kiln shelves and posts to support the shelves. You can stack your shelves up to three high if you wish. You are able to fire many pieces at once with stacked shelves.
If your pieces are of an irregular shape you may need a small terra-cotta dish to hold a product such as Vermiculite in which you can place your metal clay pieces. After a number of firings it will need to be replaced as the pellets tend to break down.
A refractory ceramic fiber blanket can also be used to hold precious metal clay pieces.
The manufacturer normally includes firing schedules with each clay product. Schedules may vary between products.
The video below is a good demonstration on loading a kiln and setting the firing schedule.
Providing you don't have glass or some other inclusions it is safe to open the door slightly and let the kiln cool with the door slightly open. If you have glass in your design open door slightly until temperature drops to about 1050 F, close door and let kiln cool to room temperature.
If you again open the door before the glass has cooled you may cause stresses within the glass which could result in cracks and breaks at a later stage. To overcome this you will need to re-fire the piece to the original firing schedule. Repeat the crash cooling of the glass to 1050 F, close door and let cool to room temperature.
Always wear heatproof gloves when removing items from a warm kiln, place hot items on an extra kiln or tile.
For important safety information please visit glass kiln safety in the home.
Precious metal clay can be fired with a butane torch, on a gas stove top or in a number of small non-programmable kilns.
Please visit Delphi Glass at Silver Jewelry Clay for details on tools and supplies.
A range of kilns and tools suitable for firing metal clays are available from Delphi.