Friday, January 22, 2010

Electrolytic Copper Etching



As part one of my mission to make my studio practice healthier for me and any future babies, I decided to give electrolytic copper etching a try. It turns out it's so easy to do I am surprised more people haven't tried it. I downloaded an article from Art Jewelry about how to do it, but you can also find lots of good information floating around the internet.
Basically, all you need to do is hook up a D battery to two pieces of copper suspended in a saltwater bath. One is the piece you are etching, the other can be any piece of scrap copper. The current draws copper from the etching piece to the scrap copper. You can use the same kinds of resists you would use for acid etching, but you don't need the etching chemicals. Neat huh?
Here's what you need:
  • D battery
  • D battery holder
  • Alligator clips
  • Heavy copper wire (14g. is good)
  • Copper to be etched
  • Scrap copper
  • Pure salt (kosher or canning and pickling salt)
  • Plastic or glass container
  • Resist (pnp film, stop-out varnish, asphaltum, etc)


To get set up, you need to attach your alligator clips to the lead wires on your battery holder. My friend Paul helped me out (thanks Paul!) because even though I know all about silver soldering I know nothing about soldering electrical components. Then you make a saturated salt solution by dissolving as much salt as you possibly can in water.

To get your metal ready, you need to get the piece you will be etching really nice and clean by scouring it with a scrub pad or heating and pickling it, then draw your design on with whatever resist you are using. I was surprised when I first started experimenting with this technique to find that the salt water is just as hard on the resist as the ferric chloride was. Permanent marker didn't work at all, and the sharpie paint pen I used to use for beads works ok but doesn't last long enough to get a good deep etch, so I am back to using the stop-out varnish (check out my acid etching tutorial for more info on different resists) The scrap copper just needs to be cleaned off with a scrub pad or brass brush to remove any residue, then it's ready to go.

Once your metals are ready, fill a plastic or glass container with the salt solution, then attach your two pieces of copper to copper wires and hang them from the sides of the container so they are submerged in the solution. Attach the positive alligator clip to the piece you want to etch and the negative clip to the scrap copper. You will immediately see little bubbles rising from the scrap copper, and within minutes the water will start to get cloudy and reddish brown with copper (Note: Don't pour this water down the drain! collect it and talk to your local waste management people about how to dispose of it. It's not hazardous to handle but it's not good to put copper into the water supply!)



It takes about an hour or more to get a really nice deep etch. Depending on what effect you are looking for, you can get a visible etch in about a half hour. I need to do some more experimentation, but my first piece has a visible etch so I consider it a success.

Overall I am very pleased with this project. It was easy to do and safe, without the mess of ferric chloride and it cost about seven dollars for all the supplies to get started. I am planning on doing a lot more copper etching with this technique, so I should have lots of new etched copper jewelry and beads coming soon!

66 comments:

Anji Gallanos said...

Thank you thank you. I have been using Ferric Chloride for a while. I also read the art jewelry article..but got confused. I have several plastic bins of old ferric chloride sitting in my studio (not sure how to get rid of it).

Copperheart said...

I have the same issue. I need to contact the local waste management authorities to get rid of it.
I'll be updating this tutorial as I learn more about the technique but I was excited to share!

MagicatGlass said...

Well, you know I love your art, even though I am not a jewelry maker like you. I enjoyed this very much and loved the etched bead :-)

Copperheart said...

Thank you! I've been making the etched beads for a while, but I decided to stop using the etching chemicals when I found out I was pregnant, so I am excited to be able to make them again.

Jaime said...

This is so cool, I can't wait to try it! Too bad there wasn't a chemical free option for silver etching!

EB Bead and Metal Works said...

Thank you for the instructions on etching. It has bee a few years since I did this in my metals class and I would love to try this again with my own jewelry.
THANK YOU!!!!

equosdesigns said...

where do you get the fabulous large copper beads? thanks for the tutorials they are helpful

Copperheart said...

Rio Grande

Cabrina said...

wow! thats so amazing im glad i stumbled upon this tutorial! i wonder where you would get a battery holder like that... i suppose you would have to make one correct?

Copperheart said...

I got everything at radio shack. The battery holder comes with the wires attached and all you need to do is solder on the alligator clips.

weirdlywired said...

Both of your etching tutorials are wonderful!!! I'll be picking up the supplies in the next couple of days and am going to try the electrolytic technique first.
I am wondering if you've ever tried the Press-N-Peel paper with the electrolytic method of etching?
Thanks so much for sharing your knowledge! It IS appreciated!!!

Copperheart said...

I haven't tried the PNP with electrolytic etching yet, but the article I read from art jewelry said that you could use it. I'm sure it would work.

Trish said...

Just discovered your blog...googled on how to etch copper...and LOVE your tutorials...so clear and wonderful of you to share your know-how!
Getting supplies tomorrow to give it a try...you've inspired me!
Thanks!!

Trish

Jan S said...

Have a rectifier that works on the same concept (love it). Does allow for more control and power, but love the less expensive method. Would like to know how you etched the round bead? Did you do it in four steps for each side? Love it...looks great.

Copperheart said...

I just paint the resist onto the bead one section at a time, then when it's all dry I suspend it from a copper wire in the bath.

riv said...

Getting really inspired about doing some etching at home. I was wondering if you reuse the saltwater (well, now saltwater and copper) over and over again, or if you need to start fresh each time you etch. The idea of more and more coppery water piling up and needing to be disposed of isn't very appealing--but the simplicity of this method certainly is :)

Copperheart said...
This comment has been removed by the author.
agent57 said...

This is an excellent tutorial! Thank you!

I read somewhere (though I can't find it again, so I really can't be sure) that you can drop steel wool into a used plating solution to remove the ions. (Copper ions will plate onto iron without an electrical current, and steel wool has a lot of surface area to attract them.)

I'm not sure if this would work the same with a salt bath as with an acid-based bath, but it might be a way to remove the copper in order to dispose of the used bath.

The evaporation method might be a safer bet, though.

Copperheart said...

That's very interesting! I will try the steel wool thing the next time I etch and see what happens.

Mel said...

Thank you so much for sharing this - IT WORKS! I was able to collect the components easily and tested it on a pendant (made from the copper in an old hot-water cylinder). I used an etch-resist pen, the same as used for prototype printed-circuit boards.

I have a small question: How long do you find the average D cell lasts for these projects? I can see this being the major expense for this technique as rechargeable 'Ds' are no longer to be found where I live. Just a thought...

Thanks again,

Melanie.

Erik said...

will do the same for my wife but with an old pc power supply :)

SueS said...

When would you put the steelwool into the solution? After you are done etching? Do you leave the leads attached to the battery when you do this? I have tried etching with this tutorial and it really worked nicely. Now I would like to be sure of ease of disposal of the copper from the solution. Thanks for a very easy to understand green solution.

Copperheart said...

Hi Sue, I haven't tried the steel wool thing. I'll have to look into it. I just filter my solution through a coffee filter to catch the residue and then reuse the solution over and over, adding a little more salt when needed.

Copperheart said...

Erik, that's brilliant. I would love to know how it turns out!

Vershion said...

I am hooked.....I love etching :)
The electrolytic process is really easy and safe. One question.....since I'm using copper, should I heat patina before or after liver of sulfur? Shawn Y

Copperheart said...

Hi Shawn, good question. I haven't done much heat patina myself, and I don't know about using it along with liver of sulfur. I'm not sure what effect you would get by doing both but I suppose you would do the heat patina first. You might be able to get some interesting color effects.

Copperheart said...

Hi everybody
I was just looking over the comments here and I realized I had said I was going to try the steel wool technique and then I never did it. I'll give it a try as soon as I get my hands on some steel wool.

Heartgirl said...

Thanks for a great tutorial. Have done loads of etching now but the peice I did last night had a shiny patch on the surface. Any ideas why this happened and how to get rid of it?
Thanks

Copperheart said...

The only thing I can think of is that it was either an air bubble or a splotch of some oil or dirt that got on the metal, acting as a resist. Probably just a fluke, I would think. If you're cleaning your metal before applying resist, and brushing/rinsing it periodically through the etching process, I can't think of anything else you can do to prevent this.

Heartgirl said...

Thanks for that, I've been pickling the metal at the start but not rinsing it during the process, will try that, thanks!

Lone Tree Studio said...

I'm keeping my fingers crossed that this isn't a duplicate posting (I didn't get the "your comment is waiting for approval" notice, so I think my computer hiccuped). I was just wondering if there is a way to do this without the alligator clips? I don't solder, so am trying to find a way around that. Thanks!

Copperheart said...

I know some people use car battery chargers, which would be all ready to go with clips attached, but it seems kind of like overkill for a small jewelry piece. I didn't know how to solder electrical components either when I started and I had one of my friends make my first battery set-up, but I have since needed to make repairs (salt water is kind of hard on metal) so I got my own cheapie soldering iron from Harbor Freight and it is so easy to do. The instructions that come with the iron and solder will be all you need to get started. The battery holder comes with wires attached and all you need to do is solder the exposed ends of the wires to the clips.

Kiku said...

Have you tried to do more than one bead at once? Just curious!

Copperheart said...

I haven't tried doing two beads at once yet but I should try it the next time I do beads and see what happens. I think I could either stack them on one wire or twist two wires together and suspend a bead from each.

andraswhimsies said...

This is so awesome!!! I will have to get the supplies to try this out ASAP!! Not only will this be great for my jewelry designs, but it will be an excellent homeschool science lesson for my boys!!! SWEET!!

christopher aka- rooster said...

hello to all. is this etching the same as the etching solution that you can purchase from radio shack? also, has anyone tried electroforming. i am very much interested in this. i am actually going to purchase all items needed to electroform soon. another thing, i saw that you had some issues with melting your metal clay at one point. i had that issue when i first started. but my point is, i also purchased some base metal clay from a new source and it is very very difficult to get mixed correctely and the two firing phases are crazy. i read the instructions very well and each test piece came out bad. my silver, i can make all day. i really wanted that base metal clay to work out. polymer clay is another medium that i have started using with my stainless wire and nickel and copper and brass. resisn and enameling are another path that i am wanting to go down. i really do enjoy this blog. this is my first blog to join. ive read several, but i like this one. your art path is similar to mine. cool.

fran said...

Hi, Copperheart and all
For those who ask about the soldering, there's an easier, cheaper way to do it. I went to use my brother's soldering iron and he had alligator clips which are a wire with a clip on each end. I attached one clip to the battery wire, the other to the copper wire, and it works....no need for soldering.

fran said...

I've been playing with this, and I'm having resist problems. I tried the DecoColor paint marker, left it in for an hour. A lot of the copper came off, but no etch. And the back, which I had covered in acrylic paint, while the paint stayed on (unlike the marker) when I removed it, the finish of the copper was off, as if the resist didn't protect it.
Any idea what I might be doing wrong?
I'm thinking of trying the stop-out varnish, but like the control of a marker. I saw the post about using an etch-resist pen for circuit boards...did you happen to try that?
Thanks so much.

Copperheart said...

Hey Christopher,
For this etching tutorial you use salt water in place of the etching chemical (ferric chloride) that you can get at radio shack. The salt water conducts the electricity and that is what does the etching. I do have another tutorial on etching with ferric chloride. As for the metal clay, I tried it for a while but strayed away from it when I found some solutions to let me do my more traditional metalsmithing in my small studio-less apartment. I never got around to trying the base metal clays although I would still like to try them someday.

Copperheart said...

Hi Fran,
Did the paint marker wear off before the copper could etch or was it still there but with no etching happening? If it wore off, it could be that your metal wasn't clean enough- try scrubbing with a scrub pad and soap and water. If the paint marker didn't wear off but there is no etch something is throwing off your set-up. Double check that everything is set up correctly and try making some fresh solution with distilled water and as much salt as you can dissolve into it.
As for the back of your piece, I'm guessing that the process of removing the paint is dulling the surface of the copper. You should be able to re-finish it by polishing or tumbling. I hope that helps- It's hard to know what could be going wrong without seeing it.

fran said...

Thanks so much for getting back to me so fast.
It's both; some of the marker had come off and some remained, but no etch. I bought these pre-cut copper discs and did scour them with scotchbrite pad and soap, but maybe not enough.
The salt solution is definitely working, the water became orange and there was a lot of copper when I filtered it for disposal. And the discs were definitely changed, the finish worn off, but just no etch.
I'll try the distilled water, and let you know what happens.
Thank You!

Copperheart said...

Also double-check that your negative and positive wires are hooked up correctly (positive to the etching piece, negative to the scrap) it sounds like maybe you are etching your scrap and that's why there's copper in the water but no etch on your piece. If the wires are reversed that's what would happen. Good luck!

House of Steward Ragdolls said...

I see this has been online for a while but I just discovered it and it works great. Here is a hint on making the job easier - grind the salt in a coffee grinder and you can mix a lot more of it into the water.

Lucrecia Mejía said...

I love this tutorial and idea! Thanks for making it available. I've been experimenting with it, had trouble finding workable a resist, and finally ordered the decocolor marker (I live abroad)and am having trouble that the resist doesn't last well. The first time I thought I hadn't been careful enough, so next time around I used gloves, double-scrubbed, etc. but the resist tends to peel up at the edges and I just can't get a consistent crisp edge and clean surface like you do. Should I "rough up" the surface? I am getting a visible etch, just not a neat one. Thanks

Copperheart said...

I usually just scrub the surface with a dry scotch-brite pad (not sure if they sell them outside the US- those green fiber scrub pads for cleaning) that gives it a bit of a rougher surface that makes the resist stick a little better. Also I usually leave the resist to dry for a while before I put it into the bath, maybe a half hour or so. I hope that helps- sorry I don't have more to give you as I haven't had a similar problem.

Tuyen Huynh said...

Hi, I found this technique very interesting! So excited to try it without any chemical.
But i am much more interested to electrolytic etch with silver. Will it works with silver or do we need to use another solution than salt and water ?
Thank you so much in advance
Tuyen

Tuyen Huynh said...
This comment has been removed by a blog administrator.
Copperheart said...

Hi Tuyen,
You can use a similar technique for silver but it won't work with just salt water. I believe you need cupric nitrate or silver nitrate.

Stonearches said...

Hi, Thank you for your notes on copper etching. As for a good resist, common nail polish works. After you finish the etch remove the polish using the usual remover. I think it's acetone based, not very friendly but it works. I used this process for years making electronic circuit boards.
Charles Parham

tomboy said...

Hello Alison! Thank you so much for this diy post! As I am new in metal-smith and had a course in electronic engineering many years ago, I found the combination of the two intriguing. We will try the experiment with my co-students on jewelry class and I will let you know, how it went.
Meanwhile, is it ok with you if I translate this post in greek (my mother language) and repost it on my blog, giving you the credit of course! I couldn't find anything relevant in greek and I know this teqnique would interest a lot of greek crafters. Thanks again!

Copperheart said...

Go ahead Tomboy. Glad you found it interesting

tomboy said...

Thanks Alison! I have published the post, you can check it out. We did the experiment as well, using a power supply at 2,4V and 1,5 Amp on copper, using a Sharpie as a resistant. It worked fine! Now that I know it works, I'll use it a lot! Thanks again for the inspiration!

Danielle said...

Hi there, I've been using muriatic acid and hydrogen peroxide. will try this hazardous free method for sure. Have you tried a resist such as adhesive shelf line paper or even Stayz-on ink (stamping ink) with this method?

Copperheart said...

Hi Danielle,
I have tried stayz-on ink and it worked fairly well but didn't last quite as long as the paint pen. I haven't tried the adhesive paper but I bet it would work.

ThunderCat said...

Hi Copperheart,

1) Did you get a chance to try the steel wool method of soaking up the copper in solution. (I would like to find a method that is relatively eco-clean to deal with the leftover copper solution.)
2) What is the best resist technique you found to have clean sharp edges on the etch. If you would, please indicate the brand of resist.
Thank you for posting your wonderful technique. Thank you for your time!
Kit

Copperheart said...

Oh I never did try the steel wool technique! I will have to remember to pick up some steel wool next time I am at the hardware store. My disposal method is to filter the water through coffee filters to get all the copper and salt sludge out,and then re-use the water as many times as I can. When the water is spent (saturated with the copper) I leave it to evaporate and dispose of the salt residue. Much less trouble than trying to dispose of lots of liquid.

Copperheart said...

oh, and I use deco-color paint pens for resist. I used to use stop-out varnish (a resist made for printmaking) which also works well but is less convenient to use.

Cynthia Walker said...

Does this technique work on sterling silver?

The Studio Rochester said...

Wire. with alligator clips already attached can be had at Radio Shack.

Copperheart said...

I do believe you can do this with sterling silver but you need a different solution in the bath. I think you use silver nitrate. I've just done copper so far because I like that I don't need any nasty chemicals around.

Kitty said...

Thank you for your earth friendly etching instructions. How do you remove the paint pen paint after etching?

Kitty

Copperheart said...

Hi Kitty,
I just scrub it off with dish soap and scotch brite. It comes off pretty easily, actually.

Unknown said...

Thank you for the tutorial! I am trying it right now.

Question how do you attach your piece to the positive wire?

Do you wrap it in the copper wire? Do you put a hole in the piece and hang it from the wire?

Copperheart said...

I drill a hole in the copper sheet, bend a hook on the end of the positive wire, and hang the copper sheet from the wire.

Luanne Bursey said...

Can a battery pack using two AA batteries be used as effectively as the D battery pack?

Copperheart said...

I never tried AA batteries, but I don't see why it wouldn't work. Anyone tried it?