My first attempt at firing combined bronze and copper clays. Photo shows placement of the pieces in the first layer of charcoal. The copper/bronze combined pieces are at the top. I placed more charcoal on top with a second layer of copper and bronze beads. Placed another inch of charcoal on that and fired the first phase with the lid off. Those are 20 gauge bronze wire loops in the larger pieces.
In my enthusiasm to find out how the combined pieces would fire, I took the container out after the first stage of firing, let it cool, then put it back in the kiln to ramp up to 1550ºf and hold for three hours. After the first hour, I remembered that I had not filled the container to the top with charcoal, nor placed the lid on, as I have done with other firings. Yikes! I opened the kiln and while everything was glowing orange, I pulled the pan out with a kiln fork, placed it carefully on the concrete floor, filled the container with charcoal, (on top of the glowing orange charcoal in the pan) and placed the lid on and put it all back in the kiln and shut the door. The kiln went back up to temperature and continued to fire for two more hours. I was pretty nervous when I took the pieces out. I was sure they would have melted or something from the first hour at 1550º without any extra charcoal or the lid. They turned out fine. No bad surprises.
Three pieces have been brushed slightly with a brass brush. The piece in the upper right has been buffed with Fabulustre on a wheel. The contrast gets lost. Even more so in bright light with a shiny piece. Baldwin’s Patina is recommended to darken the copper for more of a contrast between the copper and bronze when it is polished. I noticed that Rio Grande carries it.
I have not had much experience with torch firing silver PMC, but I really like the contrast I’ve seen between copper and silver, or bronze and silver in the pieces on Hadar’s blog. I tried some test pieces of each by filling the recessed lines with PMC3, letting them dry on a cup warmer, then sanding them until the silver clay surface was smooth and even with the fired base metal clay pieces. I used a butane torch to heat the PMC3 to a dull red glow, kept the flame moving and held the color for 2 minutes and then quenched the piece in water. The results look a little rough, but it worked. If I were making pieces to sell, I might try filling in some of the spots and lines with more PMC, and refire it with the torch to get a more even inlay.
(I knew there was a reason to save these bronze beads that came apart. They made good test pieces.)
Barbara S Fernald Jewelry 