Shortening the Firing Time – Follow-Up

There have been a lot of responses and questions about my last posting about shortening the firing time and I’d like to address them here.

First, I must say that I’ve never gone back to firing the first phase in the kiln. Firing on a camping stove, kitchen stove, or the SpeedFire® Cone System™ for Metal Clay seems to work 100% of the time. The advantages:

1. It saves a lot of time. The firing time is practically the same as firing silver clay.
2. You don’t need to worry whether you held long enough at the first phase. When the smoke is gone and the pieces darken, you can be sure that the binder has burned off completely.
3. No need to cool down between phases.
4. In a workshop situation, a lot more pieces can be fired.

Again, this way of firing replaces the first phase only. Once the binder has burned off, the pieces need to be covered with carbon and the box should be moved to a kiln for the second phase.

It’s been reported that an electric kitchen stove works just as well. It makes sense: when the pieces are not covered in carbon, the binder will burn at 400-500F, which is within the capacity of an both electric and gas stoves.

As a lid you can use just a fiber board or fiber blanket with a hole These photos were missing from my last posting.

Top view

Fiber blanket

Watch for the smoke coming out of the hole. If you are not sure (sometimes thin pieces don’t generate a lot of smoke), it is ok to remove the lid with a glove or tweezers to look for the smoke and the color of the pieces.

I have successfully fired big and hollow pieces, including rings. My advice: with complex pieces use low heat; it’s best for the binder to burn out slowly. Still, the firing time rarely exceeds 10 minutes. (Rings need to be positioned in a special way. I will talk about it in my upcoming workshops).

And finally – this works with all base metal clays: bronze, Rose Bronze, White Bronze, copper, and steels.

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