Saturday, May 09, 2009

Enamel Tests on Silver Metal Clay

It's well known that the blue and green transparent Thompson enamels work beautifully on silver, while the yellows and reds tend to react with silver. I suppose it's time to get more systematic about all the colors I'm using on silver clay. But that requires sheet metal that I don't have handy.

This morning I decided to do a quick and dirty experiment with a previous metal clay piece that inadvertently got too hot and ruined. First I cut the failure into a few smaller pieces with snips. Then I pulled out the Little Torch and firebrick and melted down the silver bits. Using some of my morning frustration (don't ask!) to fuel my work, I took a hammer to the metal and flattened one piece into a sheet, repeatedly annealing to soften the work-hardened surface. Then I polished it up a tiny bit, made small dabs of test enamels and quickly fired. It's ugly, but informative:

The Thompson Enamel colors I tested first were, left to right:
top -- lime yellow, wax yellow , egg yellow
bottom -- geranium pink, rose pink, Woodrow red

It's pretty clear that the first two yellows worked acceptably well, while the egg yellow turned an ugly brown/black. None of the pinks/reds look pink at all, but the first two might make acceptable oranges. Woodrow red however is again an ugly brown/black.

The standard fix for these reactive colors is to use a clear enamel, known as flux, or nonreactive gold foil to isolate the enamel from the silver. The way that I'm using these on metal clay textured with photopolymer plates makes that difficult. My attempts to use keum boo to isolate the enamel have not been successful. Now I know using one of the pinks would have been a better choice for my fish enamels than trying egg yellow over keum boo, see my previous post.

I'm going to order some fine silver sheet so that I can do a set of reference samples in all the colors. But now I know, without waiting for the shipment, what color to use to approximate the yellow orange blossoms on a prickly pear cactus, which is one of my current projects.