Friday, June 21, 2013

Enameling techniques: champleve, working with ferric chloride

Part of the reason why I haven't blogged much lately is because I've been studying a new enameling technique (well, new to me, anyway, since the technique itself goes back to ancient times): champleve.

With champleve, you carve out a design or groove into a piece of metal and then fill that depression with enamel. The piece then looks as if it's been inlaid with the glass and the design has a lot of depth and texture.

There are many ways in which you can carve the piece: you can engrave it, cut out an opening in one piece of metal and then solder it onto a backing (and then have subsequent pieces cast), or, as I'm doing, you can burn the metal with an acid.

Different types of metals require different acids to burn. I've been using copper so ferric chloride is my substance of choice. Silver uses nitric acid, but this substance is extremely dangerous to use, which is why I'm avoiding it. Eventually, I'll have some copper pieces cast in silver or silver plated.

To actually burn out the design is pretty easy. I start with a thick piece of copper -- 16 or 18 gauge -- and apply a resist to all of the areas that I DON'T want to burn. This means that if you want to have a triangle-shaped depression, you cover all of the areas of the metal EXCEPT for that triangle. You can use many things as a resist, but I like nailpolish because it's sticky and stays on for a long time without breaking up. The downside is that it's difficult to draw fine lines with it. A paint pen might be a better choice if you want to create a more exact, detailed design. I make sure to paint all of the necessary areas, including the sides of the metal, with the polish and then cover the back of the metal with some contact paper. I then place the metal FACE DOWN into the acid. Also important: I don't just plop the metal into the acid. I keep it suspended on some flat sponges, which I cut into strips. Whenever I remove my pieces, I use copper tongs -- and I always wear goggles, a surgical mask and latex gloves. Most pieces take at least three hours to get a nice, deep groove.

As I'm sure you've guessed, working with acid is DANGEROUS. Kids, do NOT try this at home. Actually, do not try this at all!!!!! Adults, do not try this without proper safety gear and without first learning the basics. I'm still nervous whenever I have to work with the acid. One wrong spill and you can get seriously hurt.

I keep my acid in a Tupperware container, which obviously will not be reused for food! You can store it and reuse it a few times, though it does eventually lose its effectiveness. You can't just dump it down a drain; I first neutralize it with baking soda. Again, this is serious stuff!!!

Anyway, I've managed to carve out some interesting pieces. Right now, I'm working on a series of heart earrings made on 18 gauge copper:

These aren't yet finished. The enamel needs to be sanded so that it's flush with the metal and the copper needs to be cleaned and polished. But you get the basic idea of how the glass looks against the metal. The toughest part for me, so far, has been figuring out how to apply certain colors. Because the glass is going into a groove, the colors come out much darker than they do when they're simply applied to the copper's surface. I finally figured out that it's best to first apply a coat of white or clear enamel and to then add the layers of color. You also need to heat that first coat for a bit longer than you normally would because again, the enamel is lower down.

Right now, I'm burning a square piece of metal with a square groove that will look sort of like a frame. I'm letting it sit in the acid for longer than usual because I want a very deep depression. I then plan to experiment by working with cloisonne within the groove. Next time, I'll show you a before picture so you can see what the burned-away copper looks like.

Meantime, check out my other jewelry pieces at Naomi's Designs and MayaGirl Creations.

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