How to Easily Etch Metal with Electricity

2022-07-31 | By bekathwia

License: Attribution-NonCommercial-ShareAlike

Here's an easy method for etching metal with electricity. I wanted to make some brass plaques to commemorate my brother, who passed away recently. Other methods use toxic etchant chemicals, but this method uses salt water. Both have pros and cons, but I prefer the electric method because it's safer and the cleanup is more straightforward.

12V 2A power supply
Extra long wires
Gator clips
Brass to etch
Steel to match the approximate brass size
Plastic container larger than your metal
Warm water
Salt
Aquarium pump with tubing
Aerator stone
Laser printer and iron (for toner transfer method) or Vinyl cutter and adhesive vinyl (for vinyl method)
Electrical tape
Rivets and rivet tool (optional)

Before you etch, you'll need to get your artwork transferred onto the brass, masking out everything you don't want to etch. There are a few methods for this step, as well. I first tried the toner transfer method of ironing on a laser print-out, then soaking off the paper in water, but I couldn't get the temperature and pressure worked out well enough to successfully transfer my image. So instead, I used my vinyl cutter to make a sticker of my design and stuck it to the brass.

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On the back of the brass, tape the stripped end of the positive wire so it makes good contact. Cover the entire surface of the brass with more sticky vinyl or another waterproof tape, except where you want to etch.

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Attach a gator clip to your negative wire and clip it to a piece of steel about the same size as your brass. Now that your two electrodes are ready you can, set up your plastic container fill it with warm, salty water (as much salt as you can get to dissolve) and add the aquarium aerator.

Place the metal electrodes into the solution on either side of the aerator. The two electrodes should not touch. You can use a clamp to hold one or both to the side of the container.

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Now plug in the aquarium pump and the 12V power supply. You should see bubbles start to form on the metal surfaces. I let each of my plaques etch for about two hours.

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What's happening here? It's a type of forced corrosion. The positively charged plate excites the electrons in the copper and zinc, making up the brass, and some of the atoms give up their outer shell electrons to the surface atoms, which are then called positively charged ions. They dissolve in the liquid electrolyte, breaking off from the surface. Eventually, you can see a build-up of copper in the solution. becky-stern-electro-etching-12

Before removing the sticky vinyl, I applied some blackening solution to provide contrast to the lettering. Then I peeled away the vinyl to reveal the final design. The blackening solution got under the sticker in a few places, but a quick scuff with a high grit sanding pad cleaned it up quickly.

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I cut out the smaller plaques with my jeweler's saw and cleaned them up with my belt sander before drilling the mounting holes. Then I used rivets to attach one to the coffee can, my brother's preferred vessel. I designed the artwork in Illustrator to mimic the Cafe Bustelo logo. becky-stern-electro-etching-13