Just a hint of color.
Posted by C Scheftic on 2010/01/14
Metal-smith and metal-clayer Tim McCreight is in town, teaching several workshops at the Society for Contemporary Craft.
One of them is "PMC & Color."
I made a whole collection of small pieces, mostly simple charms, to color-up in the class, the idea being that they could end up on some sort of sampler piece, perhaps a charm bracelet.
Some of them turned out beautifully, a few did not react quite as I’d expected, and some remain to be finished. Tim covered a whole range of possibilities, but there wasn’t time for everyone to complete samples using every method that had been addressed. Each participant did have time to try out a few of the ones that captured their interest the most.
One of my favorite methods involved copper-cladding. In this method, you use a bit of chemistry and a bit of physics, and what you end up with is a piece that’s covered in copper.
Now, why on earth would you take a piece of (relatively expensive) fine silver and cover it with a layer of (relatively less expensive) copper? Because, even if you like what are known as patinas, there are only a limited number of options for getting patina colors on silver. But copper is another story: there are all sorts of recipes going back centuries for getting patina colors on copper. So you coat (clad) the silver with copper, selectively remove portions of the coating, and then color what’s left.
Did you notice the copper on the image above? It’s there, in the hollows: it’s what’s been turned (by exposing it to ammonia fumes!) into the areas with that blue-ish green color!
I did not polish the copper off the the back before starting the development of the patina. So, um, it turned mostly black!
Not to worry though, it’s still easy enough to polish most of it off. Since these are just simple charms, on the other hand, I didn’t feel compelled to remove every last dark molecule.
Over the next few weeks, I’ll try to post more examples from this class and my follow-up experiments.
This entry was posted on 2010/01/14 at 20:00 and is filed under Learning Metal Clay. Tagged: clad, copper, patina. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.