Bronze clay was introduced two years ago at the PMC Conference. We were all given 30 grams of bronze clay to try. I also bought a 100 gram package. Well, two years later I'm finally giving it a try.
The 30 gram pack was hard as a rock, but I was able to work with the 100 gram pack. Since the outcome is not always predictable, I decided to just keep it simple until I saw how things were going to work. (Actually the unpredictability of the clay is the reason I waited this long. I was waiting until other people worked out all the kinks.)
Bronze (and the copper) is considerably cheaper than the silver clay. But, I found both of them harder to work with. Both the copper and bronze have an elasticity that the silver doesn't have, so joints may crack open during firing. The bronze clay is stiffer and gets stiffer the longer it is worked. It has to be cooled to make it more flexible. Since my clay was two years old I wasn't sure exactly how "stiff" it should be. (I've ordered another package to try, then I'll know for sure.)
The clay is also very "dirty" to work with. It stains the hands and creates a very dark dust. Basically I don't like working with it. (I wasn't too crazy about working with the copper clay either.) Come to think of it, my first exposure to silver clay was less than rewarding too. Who knows, maybe I will like working with it eventually.
For firing, bronze clay has to be surrounded by activated charcoal in a steel container. The container is set up on kiln posts. The pieces have an inch of charcoal under and over them. And, there must be one half inch between the pieces. For thin pieces the kiln has to be ramped up slowly, 500 degrees per hour. Once it reaches 1550 degrees, the temperature is held for two hours. This whole process takes about five hours. Finally the pieces are left to cool in the charcoal container over night.
Tomorrow will tell. I'm looking forward to opening the container (fishing out the pieces) and seeing how they turned out. Hopefully everything is good. Hopefully, taking two years to try the clay pays off. I'll let you know.