After my blog postings about Sterling Silver using Quick-fire Copper and about Copper and Silver Mokume-gane, the next step for me was to play with making mokume-gane from sterling silver clay and Quick-fire copper. (See instructions for making sterling silver clay in my posting: Sterling Silver with Hadar’s Clay™ Quick-fire Copper. Here are some of my results. The first attempt is a pair of mirror-image earrings.
To my surprise, the lentil sintered without repeating the second phase of firing.
Here is an experiment with a gradient surface:
These are double-sided spinning earrings. They are small, but pretty thick. They also sintered without repeating the second phase.
This time I fired in both my kilns, front-loader muffle and top-loader fire brick. I used a ceramic cloth, which is the same as fiber blanket as far as temperatures are concerned. The firing schedule is exactly the same as for copper and White Bronze (how convenient – and weird!). In some cases I skipped the first phase by firing the pieces with a torch on top of the carbon. (I don’t recommend doing this with thin, flat pieces, since they tend to break, and I am not sure it can be done with White Bronze). When I didn’t skip the first phase, I fired in carbon for 30 minutes.
The temperatures for the second phase:
Top-loader brick: 1250°F/677°C;
Front-loader muffle: 1325°F/718°C.
I am going to repeat this schedule several times before updating my instruction manual (again?).
I did not find any difference between firing Quick-fire Copper with fine silver or with sterling silver. The metals seemed to fuse at the same temperatures.
I did find shrinkage issues with both fine and sterling silver. In some pieces that had a silver backing layer, the backing layer curved backwards because of greater shrinkage. This could be due to the brand of silver I was using. You can try silver clays with lower shrinkage rate. With the price of silver today, I am not sure I can afford it.
Advice: if you try, test first. Start at a low temperature, sand to check sintering, and if the piece has not fully sintered, repeat the second phase. If it still hasn’t sintered, gradually raise the temperature.
Warning: Do not fire silver and White Bronze in the same box. If you want to test them both in one firing, use two separate boxes.