Silver's gone up and so has the price of metal clay. The last time I ordered it had jumped up $2. Right now I have no money (well, I have enough to pay the rent but not much else.)
So, I decided to turn to the base metal clays. I had part of a 100 gram pack of CopprClay (which was as dry and crumbly as cookie dough), part of a 100 gram pack of Bronze clay (which was hard and green), one 200 gram pack of Bronze Clay, two 50 gram packs of Art Clay copper, (the opened, but never used pack was hard as a brick and the other pack was nice.) Plus I had one vial each of Hadar's copper and white bronze clay. (It was way past time for me to use these clays.)
I also had some unfinished pieces from Debra Weld's class in August of 09. (Obviously I didn't have to worry about them not being dry.) I made some major changes to their design though since the clay was dried up. The CopprClay carved liked butter and was easy to drill through.
The first time I fired pieces from the class it went well. The second time was a partial disaster. The pieces I created in class fired fine, but the pieces I attached to them disintegrated in the tumbler. (What pretty coppery water it was though.) Today I fired more of the class pieces using a two part firing technique. I fired on an open shelf at a ramp of 500 degrees per hour to 555 degrees and held for one hour. When the pieces were cool enough to handle I put them in the stainless steel container with charcoal and fired for four hours. (The directions said 3-5 hours so I aimed for the middle.) I won't know until tomorrow morning how they turned out.
While the CopprClay was firing (which seemed like forever) , I decided to try the Art Clay Copper for the first time. Since everything with these clays is so variable, I try to keep it simple for the first few times out. The pliable clay was pretty easy to work with, except the first time it stuck to my teflon sheet. (Go figure!) It was also easy to drill but not as easy as the CopprClay.
Art Clay Copper can be torch fired, so I gave it a try. I torched from 3-5 minutes per piece. The silver clay is torched to a peachy glow and the copper clay is torched to a cherry red (which is hard to see through the safety glasses.) Immediately after torching, the piece is quenched in water to remove some of the fire scale. Then it goes into a pickle solution for about 15 minutes to remove the rest of the fire scale. Now here is where I started to get nervous. I assumed the fire scale would be black (like the picture of the copper clay in the kiln), but it wasn't. It was basically a dark red, which dropped off in the water. I didn't even have to put it in the pickle (which was a good thing...... didn't have any.) But when I went to brush the piece, a wet red color was wiping off the piece. That made me nervous since it was a reminder of the disintegrating incident earlier. They felt very hard so I popped them into the tumbler and held my breath. Two hours later they came out of the tumbler shiny and in once piece. Phew! The color isn't quite as coppery as the CopprClay though, but they're nice. And it is nice to be able to torch fire. Tomorrow I'm going to try kiln firing the Art Clay copper. It only takes 30 minutes (which is a lot better than 3-5 hours.)
The Copprclay was air dried which is what Debra wanted us to do. I dried the Art Clay copper on the candle warmer. Debra told us the base metal clays have more elasticity than the silver clay which may make more cracks appear as the clay tries to return to it's original shape. I think that is why she recommended air drying. I did notice that it was a little difficult when I tried to form a circle over the back of a paint palette. The little bugger kept wanting to pop up.
I did work with Hadar's white bronze clay once and felt the consistency of her copper clay. I may work with her clay tomorrow, but I need to use up the opened pack of Art clay before it dries out. That is the nice thing about Hadar's clay. You don't have to worry about it drying out and I know the consistency is nice and creamy not stiff like the other clays.