My newest jewelry-making technique involves a bit of chemistry and physics. I gave metal etching a try this month. Etching and electroforming are the techniques featured for the Self-Representing Artists in Jewelry Design challenge in August.
I began researching etching weeks ago, and decided on salt-water as my etchant almost immediately. My studio, which is sometimes otherwise known as my kitchen counter and dining table, is not equipped for harsher chemical techniques that generate more toxic fumes.
I reviewed about a half-dozen different tutorials before getting underway. And then I went shopping for the materials, most of which were available from the grocery or craft store. The one thing I ordered was a D-battery holder. And then, thanks to a fellow SRAJD member, I saw a tutorial that showed how to convert an ac/dc adapter to a power supply. That’s a project for next time. Because I like the idea of not generating all those waste batteries.
Every tutorial I reviewed indicated you need a saturated salt water solution for your etchant. That’s a very simple thing to make. Heat some water (simmer will do fine, no need to boil) and stir in salt until it stops dissolving. For my project, I used a 750 ml plastic container, with about 500 ml of tap water and somewhere around 200 g of Kosher salt. The measurements don’t have to be precise.
As I stood at the stove stirring and pouring salt, making the saturated salt water solution, I grew nostalgic for those magnetic stirrer set-ups we used in chemistry lab. (Did you know you can get them from Amazon? Oh so tempting.)
Prepping the metal to be etched was also simple. I cleaned the copper blanks and the scrap copper. Then I used ink and a rubber stamp to put a design on the blanks. The ink acts as a resist to the etching. In other words, the inked parts will be raised on the finished piece.
I was a little worried the ink wouldn’t work. Because in one of the video tutorials I watched, the instructor said the ink wore off after about 15 minutes. That didn’t happen to me. My ink stayed on for the entire etching and until I cleaned it off.
My etching didn’t get off to a great start. When I hooked my battery up to the copper wires there was no bubbling. If everything is set up properly, bubbles should form on the scrap copper, to let you know current is flowing and etching is in progress. No bubbles means something is amiss.
I tried changing the battery, several times. Still no bubbles. I was convinced the battery holder was faulty. I mean, this set up isn’t rocket surgery and there are only so many things you can get wrong. Luckily, my handy man came to the rescue with some wire stripping pliers and voila …bubbles! They make a soft fizzy sound, like pouring soda into a glass.
Another thing every tutorial I reviewed had in common was indicating the etching would take about an hour. I lifted my copper blank out of the solution after about 30 minutes to check the progress. It was difficult to tell if anything was happening to it. But I knew copper was being drawn away because the scrap piece was getting crusty and the water was completely orange.
I let my etching go on for about 90 minutes total. By then, the piece of copper wire suspending my blank was nearly dissolved where it was in contact with the blank. Some tutorials recommend using 14 ga or larger wire. The largest I had was 18. No big. You can take your blank out of the solution and replace the wire if you need to keep etching.
My first piece was a success. The etch is not super deep or crisp like you might get with other chemicals, but it was distinct and looked like the design I had stamped in ink.
My second piece didn’t turn out well. At all. At least one tutorial indicated you can re-use the salt water solution, even with all that copper dissolved in it. I put in a fresh battery, just in case, and put my second blank in. I left it for the same amount of time as the first. And I got lots of pitting and a very messy etch.
I don’t know for certain that re-using the solution was the cause of the pitting. But just to be safe, I mixed up some fresh salt water and tried again with a new copper blank. The results were similar to the first piece, with a distinct design and very little pitting. In fact, the third piece came out even better than the first.
I might experiment with re-using the solution. One tutorial suggested adding a little citric acid (which you can get from the canning section of a grocery store). And one suggested aerating the water, with an aquarium pump. Perhaps one or both of those would minimize the pitting?
I know I can reuse the scrap copper. It was pretty crusty and messy looking after the first etching, but also very easily cleaned up. Most of the copper salt wiped off with a paper towel.
After I cleaned up my two usable blanks, I highlighted the etch with a liver of sulphur patina. And then I was ready to make some earrings. I saved the pitted messy blank and will probably see what happens when I add some Iced Resin enamels to it.
For the earrings, I added some green Picasso-finish Czech glass flower beads and copper rondelles as accents. They’re hanging on patinated copper wires.
I’m quite pleased with my first etching attempts. I’ll definitely be doing more of this in the future. It apparently also works on brass. The two etched copper focals didn’t turn out exactly alike. One has a deeper cleaner etch (and a slightly darker patina) than the other. I like them both. And I think they make an interesting pair of rustic earrings.
Edited 31 August 2015. Please note this is not intended as a tutorial. I encourage you to review the links I’ve shared, or do your own search, for the detailed steps. Also note that salt water etching is still a chemical process. Appropriate safety precautions include protecting your eyes from splashes. And those bubbles are hydrogen gas. Not a lot for a project this size. But if you were doing this on a larger scale, you might want to consider appropriate ventilation. Just in case.