More Options for Firing Copper

So far a few options have been suggested for firing Quick-fire copper clay:

1. Torch-firing (for small pieces only);

2. Hot firing – putting the piece in a hot kiln, removing it while hot, and quenching in water;

3. In a fiber blanket box, with a little carbon, for two hours.

The third option is the same as the method mentioned in the Quick-fire bronze schedule, except that it requires two hours instead of just one.

Actually, there is an another possibility, which does not require handling a hot kiln or waiting 2 hours. If you fire copper alone, you can compensate for time with temperature. (This is true for copper, but not for bronze!) I fired copper following the firing schedule for Quick-fire steel clay. I went up to 1800°F/982°C in my top loader kiln (1880°F/1026°C in a front loader kiln), and held for 1:00 hour.

Here are the photos of before and after:

Before

Out of the kiln

Out of the kiln

Finished

Finished

You can find the instructions for making a spinner bead like this in my book: Silver and Bronze Clay: Movement and Mechanisms, pp. 88-94. In this case, the bead and the spinner are fired at the same time.

Before

Out of the kiln

Out of the kiln

Finished

Finished

As you can see from the second example, unlike copper and silver, copper and steel will not alloy and melt as a result of spending a long time in contact under high temperature.

Without steel present in the box, it does not seem necessary to fire at such a high temperature. So my fourth suggestion is:

4. Place in a fiber blanket box with a little carbon on the bottom and on top, with no lid.

Fire at 1690°F/920°C in a top loader; 1770°F/965°C in a front loader.
Hold for 1:00 hour.

Of course, the larger the pieces, the more carbon and time are required.


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