Still not having much luck with the firing. As a recap, I planned to refire a number of pieces of bronze clay which were under-fired first time around. In the same tub I included two copper clay “bags”.
This is the schedule I used.
- Ramp: 253 F per hour (137 C)
- Target (Hold) Temperature: 1530 F (830 C)
- Hold 3 hours.
All the copper crumbled.
Rio Grande’s recommended firing schedule is as follows:
COPPRclay™ Firing Schedule (for pieces that will not be enamelled):
Regardless of thickness (embedded in coconut shell-based activated carbon): Ramp at full speed to 1700°F-1800°F (927°C-982°C) and hold for 3 hours (total firing time, including ramp-time, will be about 4 hours). Most firings perform well at 1700°F. However, if you discover that your pieces are not sintering properly, try firing them at 1800°F. Please Note: Blistering may occur at 1800°F; if this occurs, slightly decrease the firing temperature.
If I went by this I would say the problem was obvious. The kiln was not hot enough but I was used Hadar’s original copper clay not COPPRclay. Hadar’s schedule is as follows:
It is bit more complicated but not as hot. Perhaps missing the first phase was the problem.I have not yet had any success with copper clay although I have only tried Hadar’s original clay. I have a package of CopprClay lying around so I may try that next.
I wasn’t really expecting the bricks to fire properly. As you can see, I wasn’t disappointed;)
There was one success. I repaired the broken bail on the landscape pendant. It came out of the kiln with a nice patina but it wasn’t quite what a wanted. After a bit of sanding and tumbling it came up more how I wanted it to look.
A added some blue resin in the hole as enamelling sounded all too hard. I’ll call it “Blue Moon” after last weekend’s Canberra moon.
