Sunday, August 2, 2009

Copper Acid Etching Tutorial

So, I spent a lot of time today documenting my copper etching process, so I figured I might as well turn it into a tutorial. Let me emphasize that I'm not including all the safety procedure, so please read more in-depth about this if you haven't used these materials before. Without further ado, though, this is what I've been slaving over all day!

Step 1: Acquire materials

  • glass pan
  • ferric chloride etchant solution
  • scotch packing tape
  • cut out copper pieces
  • sharpie paint pens
  • scratch tool
  • patterns you'll be etching
  • safety gloves and goggles
  • well ventilated area

Step 2: Clean metals

This step is the most annoying part of the process. I usually use gloves, Fantastic, scotch brite pads, and running water to achieve ultimate metal cleanliness. You really need the metal to be super-clean for etching and enameling to take, so I scrub those babies till they sparkle.

Below is an example of a dirty and clean piece of copper. Dirty on the left, clean on the right. Water will always bubble up on dirty copper, but it'll slick right off clean copper. The picture below that one is all the pieces of copper clean and ready to go!

Step 3: Apply Resist

Taking the advice from my favorite enameling book out there "The Art of Enameling" by Linda Darty, I got myself some Sharpie Paint Pens that act as a FABULOUS resist for acid etching copper. I draw out my pattern in pencil on the copper first, then trace that in Sharpie paint pen, then go back over with a scratch tool to clean up the often too-thick lines.

It is difficult to see it in this picture, but I included it anyway to emphasize... don't forget the edges! I draw a coat or two of the sharpie pen along the borders once I've got the patterns drawn on the surface. Then, I attach the tape to the back of the pieces, cut off the excess tape so that just a circle remains on the back to protect it from etching the back.

Step 4: Etch!

There's lots of safety involved that I'm not going to go into too much detail about... please look that info up before you do any of this, and not hold me responsible for any ferric nitrate you ingest or something like that. These materials ARE hazardous and DO require safety procedure to be followed. This tutorial is just to show my process!

What I do is pour the ferric nitrate into the glass container, wearing gloves and eyeglasses, and in my well ventilated area. Then, I attach a long strip of tape to the back of the copper pieces, and attach them to the sides of the glass container so they can be suspended, floating with their etchable surface touching the ferric nitrate. This allows air to escape from the chemical reaction the etching causes, and allows the metal to etch easier.

Step 5: Wait Forever

Etching can take anywhere between 30mins to a few hours to overnight, depending on the strength of the ferric chloride you're using. Mine took about 3 hours today, and I checked on it every half hour to make sure it wasn't eating too deeply. I did this with a metal tool to gauge approximately how deep it had eaten into the metal, and how much further I needed it to go to be able to put a good deal of enamel in that etched space.

Step 6: Remove and clean metal

Taking the copper out is really simple, I just take the tape off the glass container, remove each piece, and then clean them in a bath of ammonia and water to neutralize the ferric chloride. With gloves and goggles! At this point, I scratch off the Sharpie pen as well, cleaning the metal and prepping it for enameling.

Step 7: Admire hard work

This is how they turned out! I think these ancient inspired patterns worked really nicely.


  1. Thanks Eric! Dig your blog too... I used to live in Philly and go to Brave New Worlds!

  2. Very cool. I love tutorials. Those look great too.