This is a simple and fast etching, also known as electrolytic etching, that is made without the use of polluting or poisonous chemicals: only water and salt, and energy.

Vote for me in the contests if you like my instructable, and post photos if you make it!

Any comments or tips are welcome, as I'm just started and still learning.


I will write more different supply you can use at the end of the instructable, like a tattoo machine, instead of the batteries (a way more earth friendly and efficient way to do the etching).




-a copper piece to etch;

-electric tape.


-a transparent container;

-a flat long piece of copper sheet;

-INSULATED alligator clips;

-battery holder and wire;

-1/8" unshielded stainless wire;

-exacto knife.

Step 2: SAFETY

I'm not responsible in any ways of damaging to items or people doing this project: use every safety steps known for every chemical or electrical projects.


-Turn ALWAYS off, or unclip, any electric device you are using, before touching anything, the water, any of the items in the bath, or touching any of the part involved in the project;

-Use glows, not to get in contact with any of the chemicals or parts involved;

-Wear every appropriate safety gear.

-Do not ingest any of the components of the project :)


This was my first etching attempt, so I used electricity from batteries, as I had them available, but in the future I will definitely only use some other device that doesn't need batteries, as they are pretty polluting (I will talk about at the end of the instructable). You can also use rechargeable batteries.

So take your battery holder, fill it up with D batteries, and add the alligator clips as in the photos at the end of the + and the - wires connected to the battery holder.


Cover the front part of the piece that you want to etch with electrical tape (or duck tape).

With the xacto knife cut away the part that you want to be etched (I just made a random figure to show how to do).

Make sure that the edge of the tape where you don't want the etch to happen are really well adherent to the copper, so any solution will get from the tape and the sheet.


Tape the copper long flat piece to the back of the copper component that you want to etch and make sure it touch it really well.

Cover all the back and the sides with electrical tape, making sure you don't cover any part of your design.


Warm up your water and dissolve the salt. The ratio of salt to water should be about 1 to 5.

Make sure the salt dissolve completely.



Bent the stainless wire as in the photo: it should have an hook on one edge to hold to the side of the transparent container, and the other side wrap in to a large hoop, large as the bottom circumference of your container.

The hoop should touch the bottom of the container, so the middle straight part of the wire should be as tall as your container is.


Place the copper piece in the container full of water and salt solution, bending the edge of the copper long piece like an hook, and hanging the piece of copper you want to etch in about the middle part of the container.

Place the stainless wire inside of the container, on the opposite side of the copper, with the ring touching the bottom.

NOTE: the copper components and the wire should NOT touch each other.



Connect the alligator clip to the metal parts:


-AFTER THE POSITIVE TO THE EDGE OF THE COPPER that hold the piece you want to etch.


If the device is working you should immediately see small bubbles coming out from the copper and the stainless.

Than a yellow dust, than green. It always change a little bit the color.

The etching can take 20 minutes up to 45 minutes, depending on how deep you want your etching, how strong is the power, how wide is the part to etch, etc.etc…

Thiner cut in the electrical tape to etch will take longer to etch, wider exposed surfaces will etch faster.

I suggest to check your work every wile, so you make sure you have the desired result.

AGAIN: turn off any electricity before handling any of the components of the project.

Step 11: DONE

Done! This is the first piece we etched.

Wash well with water and soap, using gloves, all the metal components you used in the solution.

Keep reading for more tips, and different material to use.

Step 12: LEFT OVER

Allow to sit the salt and water solution for a night.

You can reuse the salty water for your next project, just pour it slowly in another container, avoiding pouring any deposit. The bottom orange matter that you see is copper, you can dump it in your garbage, or recycle it with your scraps. It is also a good base for many patinas.

MAKE SURE not to touch the solution or the bottom left over with your bare hands, USE GLOWES.


Instead of the battery holder you can also use:

-a tattoo power supply (they sell them now online as cheap as 20 or 30$). It is nice as you can adjust the power from 5 volt, but also lower. Higher is the voltage, faster is the etching, but lower is the voltage and more precise is the etching. REMEMBER: do not use a voltage higher than 5 volt. The negative always go first, on the stainless wire.The positive always go on the part you have to etch.

-a 5 volt telephone charger. You split in half the cord, attach the alligator clips at the edge of each wire.

make sure to know what is the positive and the negative wire. The negative always go first, on the stainless wire.The positive always go on the part you have to etch.

Instead of the electric tape, to mask your piece, you can use:

-duck tape;

-nail polish (than you scratch the design you like with a sharp point);

-spray paint (than you scratch the design you like with a sharp point).

Step 14: !!!READ!!! USEFUL TIPS

This are some important things you should know and remember about this project:

-Make sure the salt is completely dissolved in the solution, and the solution is cold before use it. If the stainless wire touch the salt it won't work.

-Make sure that what you are etching is not touching the stainless wire in any place, if they do it wont work.

-Always attach the negative first. The negative is always on what you are NOT etching.

-Attach the positive to the piece you are going to etch.

-ALWAYS turn the power off before touching anythings.

-Wear appropriate safety gear (gloves, apron, eye wear…).

<p>It does...</p><p>But it seems some water came under the masking tape, and it worked a lot faster then I expected.</p><p>Got this result in under 15 min's, with nice green foam bubbling on top of the water.<br><br>Tips for nex time;</p><p>Try less salt, 3 table spoons on a little under a liter might be a bit much.</p><p>Use batteries in stead of a power supply, got 6 Volts and at the end the Amps jumped all over the place. Or tweak it a bit better.</p><p>Don't hook the + wire in the eye, etched a nice deep hole there, better get some more contact area.<br><br>All in all, glad I came across this...</p>
<p>It come out nice, thanks for all the tips and posting the photo</p>
<p>Will this work on chrome plated brass?</p>
<p>quick question, can you use sharpie as the last for the etching? like with acid?</p>
<p>I don't think it would work, but I never tried</p>
<p>i tried it with the sharpie. it does work, but you have to redraw at about 15 min. how ever if you use the sharpie paint pen it works perfectly. ^_^</p>
I have heard that if you use nail polish or glossy spray paint it will also work, you should also do a couple of coats.
<p>Nice to know!</p>
<p>can you do it on steel as well?</p>
<p>Wonderful, I want to do this now!!</p>
<p>I wonder if you actually mean &quot;gloves&quot; under safety tips at the top and also in step 12?</p><p>This is a great instructable, thank you, although for a novice like me I wonder if I could figure out how to attach the wires to the battery holder. I suppose I could talk to my friendly local Radio Shack guy.</p><p>My husband and I had to replace a large copper pipe (I believe it was a vent from the furnace) under the house, and now I have a wonderful source of copper that has a gorgeous green patina on the inside. The pipe must be 3-4&quot; in diameter. I have no idea how much something like this would cost these days.</p>
<p>Why not use something that you would like to copper plate, instead of a scrap piece of wire with the negative electrode? Make an interesting 1/2 copper, 1/2 nickel colour piece.</p>
<p>Nice tutorial ! You can also buy larger sheets of copper ( flashing ) and just cut to the size you want :)</p>
<p>If you go to the Lowes hardware section there will be an entire aisle filled with drawers containing fasteners and other bits. One of these drawers, labeled &quot;Special Projects&quot; or words to that effect contain pieces of heavy copper plate that are about 6&quot; X 4&quot;. I think that the copper sells for something like $6 which is highway robbery, but which is also a convenient way to find copper plate locally. Another good source of copper, brass and other metals is one of the many online metal suppliers, companies specializing in the sale of smaller pieces of metal as opposed to local metal suppliers that typically only sell by the whole sheet (approx. 6' X 8').</p><p>Finally, if you have or have access to a Cricut machine it is possible to cut amazingly intricate stencils cut for etching. I use Contact Paper, which sticks the best to metal when electro or acid etching.</p>
<p>This is the standard ground used in printmaking: Senefelder's Liquid Asphaltum and is available through Graphic Chemical and basically anyplace that sells printmaking supplies.</p>
<p>you can buy cooper sheets from jewelry supply places or metal making supply places.</p>
<p>You can get copper from places that do detailing for roofing.</p>
hi, can i use this method to etch pcb?
<p>Yes.</p><p><a href="https://www.instructables.com/id/The-Saltwater-etch-process/" rel="nofollow">https://www.instructables.com/id/The-Saltwater-etch...</a></p><p>And to prove it, I did it in step 4 here ... </p><p><a href="https://www.instructables.com/id/Pinebox-Electronics-Design/" rel="nofollow">https://www.instructables.com/id/Pinebox-Electronic...</a></p><p>but it's yukky -- also when the 'ible says &quot;no poisonous chemicals&quot; -- other than a gentle aroma of chlorine while running. :)</p><p>Higher voltages are faster, leading to interesting underwater sparks, and even more furious production of hydrogen/oxygen (from the water) and chlorine (from the salt) so don't push it too high.</p>
<p>Thanks,</p><p>I'll try it.</p>
<p>I don't know nothing about this</p>
<p>Would this work with stainless steel, I mean I'm sure it would, but have you tried etching steel?</p>
<p>It does work on stainless. i have done scissors with it</p>
Thanks for your reply, is the technique exactly the same? I suppose it would take longer to etch steel...
<p>I have not done it exactly like this, but with a q-tip i did my initials in about ten minuetes.</p>
<p>Should work with other conductive metals, but I only tried with copper.</p><p>I know it doesn't work with silver.</p>
<p>Awesome but why only 5 volts? I am going to try this now. Thank you so much. </p>
<p>You are welcome.</p><p>5 V because an higher V will be faster but way less precise.</p><p>As lover as the V as slowest is the process, but as more precise is the etching.</p>
<p>Ok now I understand . Thank you so much.</p>
<p>Insulated alligator clips are a good idea.</p>
<p>Good idea, I will add it to the instructable</p>
does this etch deep enough so you can create stamps?
<p>yes, the longer you work on it, the deeper it gets</p>
awesome, I'll give it a go this weekend ?
<p>Good ible! You can also buy etch-resist in a felt-tip pen made for making printed circuit boards. It's not so good for covering large areas but should be useful for finer details.</p>
<p>i usually use 12volts i hook the positive to the metal then the negative to a q-tip wet with the solution. you can control the depth more</p>
<p>Great tutorial. Thanks for all the safety info too. ;)</p>
<p>Thank you!</p><p>I tough the safety instructions was kind of funny but than I just wrote them anyways, although this is not really a dangerous project!</p>
where can I get copper sheets? I looked at home depot but they didn't have any.
you can use copper pipe, just cut longitudinally a section of copper pipe with a pair of metal shears, then hammer it or use a hydraulic press until you get a nice flat plate
<p>That's a good tip.</p><p> They sell copper pipe at Lowe's too. </p>
<p>I only use scraps, I buy old copper dishes and trays at the flea markets when I found them cheap and ugly enough so I have the courage to chop them in pieces.</p><p>You can also google copper sheet and buy some online.</p>

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