1. You'll need an etchant solution. This can be found numerous places. I got mine at Radio Shack. It's called PCB Etchant Solution and contains ferric chloride. Ferric chloride solution is also available online through Rio Grande and many other suppliers. (The hazardous material transportation fee will shock you!)
2. Copper sheet. Clean the copper before use. It oxidizes quickly so do this step right before you start. I wiped it down with rubbing alcohol as a last step to get rid of oily fingerprints and such.
3. Fresh Sharpie marker.
4. Plastic tub. I used a margarine tub because I only cut out a small square of copper. You could probably use a plastic paint tray liner for larger pieces.
5. Disposable rubber gloves.
6. Safety goggles.
7. Respirator. I did the etching outside wearing a surgical mask and didn't smell a thing. If you do this inside, definitely wear a respirator.
8. Tweezers.
9. A handy source of water for rinsing.
10. Paper towels to wipe up spills. This is important because the solution stains anything instantly!
Cut your copper to the size you want. Start small until you're comfortable with the process. Use the Sharpie marker to freehand a pattern on the copper. Remember if this is for bead caps, you want a small design. The back of the copper will need to be covered as well so it doesn't etch. I was in a hurry and the piece was small so I just used the Sharpie to cover the back completely. I understand you can use things like contact paper or even large tape as a resist on the back - I can't confirm that since I haven't tried it. I used the marker and it worked.
Place your copper in the plastic container and carefully pour the etch solution in until it covers the piece completely. The directions on the bottle said to agitate the container to keep the solution moving. I used a circular motion to gently swirl it around - no splashing please. I confess to not doing that the entire time. I get bored easily and standing outside swirling a margarine tub isn't my idea of a good time. I checked every couple of minutes and gave it a good swirl. The timing depends on how deep an etch you want. I was impatient and only left it in for about 10 minutes. It clearly needed longer. Next time I will likely go for 20 to 30 minutes.
Use the tweezers to pick up the copper and tilt it to let it drain thoroughly. Use a paper towel to wipe it off and hold underneath for any possible drips then take the copper to the sink and rinse. I held the piece very low and directly over the drain because someone said the solution can stain the sink too. For bigger pieces I would probably have a second plastic tray filled with water to rinse it in. Remember this is a toxic chemical and needs to be disposed of properly!
All that remains is to buff the marker off, cut out your caps using the best portions of the design, center punch a hole, smooth the edges, polish, dome, and you're done. Voila - etched bead caps!
Disclaimer time - try this at your own risk! Read all package directions carefully and follow precautions. Ferric chloride is TOXIC so use extra care at all times! And I remind you again to start small so you don't potentially waste an entire sheet of copper.
Now go etch some caps!
I just got some new and valuable etching information from a forum friend on Torch Bugs. Thank you Kristi!
When cleaning your metal if you run water over it and see any beading of the water, you need to clean it again. I learned the hard way! any oils you miss will affect your etched design.
When mixing the ferric chloride crystals, do not use tap water. The chemicals in tap water vary from city to city with different additives. Use distilled water whenever possible.
To agitate the ferric chloride during the etching process I have an old aquarium pump with an air stone that I put in and turn on. This vibration facilitates the etched residue to fall to the bottom of the tub and keeps the exposed area of metal etching continuously.
While etching, the metal shouldn't be touching anything. It's best to stick your piece onto a strip of duct tape. Get some scrap Styrofoam and put some double sided tape and press it on to the Styrofoam so the metal you want etched is facing down. then it will float in the ferric chloride.
When you are finished etching, to neutralize the ferric Chloride, submerge your metal in a solution of water and baking soda ( I use 2 cups(473.2ml) to 1/4 cup (59 ml) baking soda. This will neutralize the acid. Wait a minute after it stops foaming. Rinse well. Refill the tub with a little more water. Add about 1/8 c of ammonia. This acts as a stop bath for the acid and completely stops any leftover or trapped acid. Under running water, or submersed, pull the tape off your metal.
Ferric Chloride will stain just about everything it touches so be sure to cover your work area. I use newspaper.
There are varying degrees of opinion on whether you can re-use the ferric chloride. You can, but with each use it becomes less potent and takes longer and longer to etch. A batch of solution is good for about 5 hours of etching.
The solution must not be put down the drain because of residual copper ions left in it. To make it safe for disposal, you can add sodium carbonate (washing soda/soda ash) or sodium hydroxide to it to neutralize it, until the pH value goes up to between 7.0 and 8.0, testing it with indicator paper. Copper will be deposited as sludge. Allow the sludge to settle, pour off the liquid, further dilute it with water and then it can be poured down the drain. Collect the sludge in plastic bags and dispose of it as required by your local waste authority.
Never pour unwanted etchant into a toilet bowl or stainless steel sink , it will result in an intractable stain.
Kristi sells her beautiful work on Etsy or visit her website.
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