You read that right: You can etch layered metal, revealing a different-colored metal under the surface, and you can create even more color after the metal etching process by using patina solutions and heat patina. You can learn how to do all of this in our exciting new jewelry-making video, Color Contrast Bimetal Etching with Noël Yovovich.
In the video, Noël etches a unique two-layer metal that is made of copper and silver–specifically a layer of copper that has been bonded onto sterling silver (available from Reactive Metals Studio among other stores). “The advantage of copper/silver bimetal or the bimetals that use copper alloys (like shibuichi and shakudo) is that the copper metals can be etched,” Noël says, “plus the color, even without patina, is a strong contrast with silver. So etching away parts of the copper to create imagery was a natural way to go for me. Add in piercing and overlaying the result over titanium, and you get the kind of detailed imagery that is meat and drink to me.”
“Even without the piercing, etched bimetal gives a result that is a lot like marriage of metals, but a whole lot easier,” Noël says. It’s easier because there’s no torch work or soldering involved. So you can get the look of a pierced copper design overlaid and soldered onto silver without having to actually solder or otherwise attach it. Pretty cool! Plus of course you can etch with extreme detail easier than you can pierce that same level of detail in metal sheet. If you don’t want the texture that comes from metal etching that you wouldn’t have in marriage of metals, you can run your etched piece through a rolling mill to take the dimension down.
“One of the things I have been best at all my life is drawing,” Noël says, “and etching has always been a way to bring drawing into my jewelry. Etching bimetal kicks it up a notch, because the drawn-and-etched image stands out so clearly.”
Did You Know: Citric Acid for Metal Etching and The Edinburgh Etch
Adding citric acid to your ferric chloride metal etching solution is a catalyst that will make the solution cleaner, longer lasting, and quicker. Did you know that citric acid, which you can buy in the pickling section of a grocery store, also helps keep the ferric chloride free from the sediment that can form during metal etching? “When you add citric acid to the ferric chloride, that keeps it clear; it doesn’t produce sludge as it etches that can block the etching action,” Noël says. This allows you to etch metal face up, because the main reason we suspend metal to be etched upside down in the ferric chloride bath is to allow the “sludge” to fall off and not get in the way.
Ferric chloride with citric acid added creates a new etching mordant known as The Edinburgh Etch, for which you can find formulas online, “but the truth is, how much you need to add is ‘some,'” she adds with a chuckle. If you’re one of those folks who want to know the specific amount, I looked it up for you. Friedhard Kiekeben, who created The Edinburgh Etch method, suggests using four parts ferric chloride and one part citric acid solution, which is three parts water and one part citric acid powder.
Bimetal etching is such a unique, versatile metal etching technique. What will Noël think of next? “I recently tried enameling on etched bimetal, but my first attempts reminded me that two different metals [heated] in close contact tend to make an alloy . . . that is, melt together. It may still be possible, with a great deal of care,” Noël says. “Next up will be to try etching some of the silver after I’ve etched the copper!” I can’t wait to see how that turns out! Get started with your own metal etching experiments with the Color Contrast Bimetal Etching Collection, which includes Noël’s video and an agate burnisher to help get you started in metal etching–or just get the video alone if you don’t need the tool.