Copper Clay

Finally the long awaited copper clay has arrived!
In the photograph above are our first experiments with this exciting new clay.
In its clay stage copper looks very much like bronze but feels somewhat like rubber, it also cracks less easily. The clay was used straight out of the packet without refrigerating it first, so the rubbery-dry feel might disappear if stored in a fridge.

We use a top loading brick kiln for firing, the pieces were placed on 1 single layer and distributed evenly in the middle of a tall pan, with coconut based carbon under and over. It's a good thing to gently tap the top carbon layer to avoid any air bubbles being trapped which would result in oxidized pieces.
Why don't we fire several layers together? whilst working with bronze clay we found that the best results by far were achieved by firing only 1 layer at a time, so we continued to use this method with copper.

Firing schedule:

The instructions on the packet suggest ramping at full speed to 1700° (927°C) and hold for 3 hours. Again, thinking of our experiments with bronze and how we've had to shorten the hold time and lower the temperature, we again worked towards the same direction with copper and tried the following:

For a 2300 watts kiln:
1 hour ramp to 1650°F (900°C) and hold for 2 hours. Total firing time: 3 hours.

We left the pieces cool in the shut kiln until the temperature was 390°F (200°C) and took them out. This took about 5 hours cooling time.

With this method the pieces shrank by approximately 20% but turned out to be very strong and didn't break or snap. The texture applied in the wet clay stayed intact.

The hearts were brushed with a brass brush and burnished in a tumbler for 1 1/2 hours.
They came out very shiny and a beautiful rosey-coppery colour.

Hopefully this post will give hints and help others in their quest for the perfect metal clay object. ;-)