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Picture of How To Electro-Etch a Solid Metal Plaque
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This is a technique that has been used by humans for a very long time.

Learn how to create a deep electro-etched metal plaque with household items or items from the hardware store in this Instructable.  There are no hazardous chemicals (except dihydrogen monoxide and salts of sodium and chlorine), no dangerous voltages, and no toxic chemicals to dispose of.  Be aware that the metal that disappears from your etched metal does end up in the water, so you will need to pay attention to any local laws about disposal of metal particulates.

This is a great technique that makes it really easy to go from virtual artwork of any type to a dimensional 3D surface.  From there you can use it ti burnish and emboss paper, create molded items, make stamps, steam punk data plates, or anything else where you need to have 3D art from your 2D computer graphics artwork.

In this sample project, I will be creating the plaque from a 1/8" rectangle of brass as shown in the second photo.

So read on if this is something you would like to be able to do yourself.
 
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Step 1: Here's What You'll Need

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You will need the following items and supplies:
  • Piece of brass, bronze, aluminum, steel or stainless steel, or any other metal
  • Vector graphics program or other program to create the art for the CNC vinyl cutter
  • CNC vinyl cutter
  • Self-adhesive vinyl sheet for the vinyl cutter, any color is fine
  • Tub large enough to hold your piece of metal
  • Salt
  • Water
  • Battery charger or charged car battery (or other similar DC power supply of 5 to 10 amps or more)
  • Wires to connect the power supply to the piece of metal
  • Sacrificial piece of metal (preferably stainless steel, but any metal will work)
  • Electrical tape

Step 2: Create the Artwork

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Use your favorite vector graphics program to create the artwork.  I used Adobe Illustrator, but you could use any vector-based design software including Autodesk Inventor, Autodesk 123D, Inkscape, or others.  Any shapes you create will result in the raised areas on your finished plaque, and the areas where there is no artwork are the areas that will be etched away.  Try not to make the details too small because the vinyl cutter doesn't really do a great job with tiny cuts.

You might need to perform an operation to convert any live text into vector outlines.  The resulting artwork from this process is shown in the second photo.

The artwork shown is from my first pass through this project.  Because the very tiny type of the tagline under the TechShop loco ("BUILD YOUR DREAMS HERE") and the "TM" by the letter "p" in the TechShop loco were peeling off on their own,  I took those out of the artwork.

Step 3: Cut the Mask with the Vinyl Cutter

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Use the CNC vinyl cutter to create the vinyl mask.  The exact procedure will depend on your particular vinyl cutter.  After you have cut the vinyl, "weed" out the unwanted areas from the cut leaving only the parts of the artwork which will represent the un-etched areas or high areas on your plaque.  After the unwanted areas are weeded away, place the backing sheet over the face of the vinyl mask and peel off the original vinyl backing sheet.

This vinyl cutter is at TechShop San Francisco, but all TechShop locations have a CNC vinyl cutter.

Step 4: Apply the Vinyl Mask to the Metal

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Clean the metal completely and make sure it is dry.  Apply the vinyl mask to the metal, burnish down all the pieces and peel off the backing sheet.

Instead of "weeding" the unwanted vinyl before you place it onto the target surface, you can also just apply the entire cut vinyl with the backing sheet, and then weed it after it is on the target surface.  In this case, I found that to be much easier.

Step 5: Prepare the Metal for Etching

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Connect a piece of wire to the back of the metal.  You can do this with solder, an alligator clip, or by taping the stripped and splayed wire to the back of the workpiece with electrical tape (as I am doing here), or any other method you can think of.  After the wire is securely attached, wrap the back of the metal with electrical tape or an extra piece of vinyl sheet.  Cover all areas on the back and sides that you do not want to be etched.  Any metal that is exposed will be etched.

Step 6: Prepare the Sacrificial Metal Piece

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Connect another wire to the piece of sacrificial metal you have selected.  In this photo, I am using some scrap galvanized steel for the sacrificial metal, but stainless steel is the best because it doesn't degrade and keeps the salt water cleaner.  You do not need to mask off anything on this piece of metal as it will not be etched.

Instead of a sacrificial piece of metal, you could use a stainless steel pot and put the negative (-) alligator clip right on the rim of the pot.  You would then put the workpiece into the pot, along with the salt water, and etch right in the pot.  You just need to make sure that the workpiece does not contact the pot electrically.

Step 7: Prepare the Etching Tank and Salt Water

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Measure out enough water to cover your pieces of metal by about an inch or two, and mix a lot of salt into the water.  The more salt, the better it will conduct electricity and the better it will etch your metal.

Step 8: Prepare to Electro-Etch

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Place your pieces of metal in the tub of salt water.  Connect wire from the piece of metal you want to etch to the positive (+) terminal of the power supply, and connect the wire from the sacrificial piece of metal to the negative terminal (-) on your power supply.  Then place the pieces of metal in the tub of salt water and place them as far apart as possible.  Make sure the side of the plaque that you want to etch is facing up.

Step 9: Electro-Etch Your Plaque

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Turn on the power supply, and you should see bubbles start to come off the surface of your plaque.  Leave it to bubble for as long as you want.  The longer you leave it bubbling, the deeper it will etch.  If the salt water becomes really dark after a while, you can turn off the power supply and replace the water with new salt water and continue.  Be careful if you let it etch too long because you will start to get "undercutting" where the metal starts to get eaten out from under the vinyl mask.

In the photo, you will see a divider separating the tank's right and left halves.  The divider is only a chopstick and is only at the surface of the salt water, and serves to keep the red scum on the left side of the tub so I can see the plaque as it etches.

Step 10: Behold Your Creation

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When you are happy with the depth of the etching, turn off the power supply and remove the plaque from the tub.  Rinse it off, and remove the vinyl and tape.  Remove the wire.  Your plaque is complete!

After I etched this plaque, I took it over to the sandblasting cabinet and sandblasted the whole surface, then I used an orbital sander to smooth the surface of the raised features to get the look that you see.

After I was done, I noticed that the copper/zinc chemicals in the salt water had stained my finger nails a beautiful shade of turquoise.  This was an undesired effect.  i suggest that you wear rubber gloves when you reach into the tank to grab your workpiece!
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btw i think the green tinge is actually due to the chlorine gas produced
TechShopJim (author)  hwilliams231 year ago
You might be right! However, it did not smell anything like chlorine. The green color was just like the color you see on brass and copper when they acquire patina.

You're right, it's the hydroxide reacting with the copper. You'll get a vile shade of brown with iron(III) and a dark green with iron(II).

johnnybravoesq made it!11 days ago
I made a rustic version of this for my great grandfather's grave.
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mshalaby2 months ago
I did it but it gave that result? Why?
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Look like really low current over a long time. Since salt water does produce some small of chlorine gas [dissolved in the water], this can cause chemical pitting as well!

Washing soda might work better, sodium nitrate is used 'in the industry' for a smoother finish, and it does not form acids.

TechShopJim (author)  mshalaby1 month ago

Hi MS...

That's weird.

The only thing I can imagine is a problem with the power supply, or your metal has a coating on the whole surface like maybe some sort of varnish.

Are you using a DC power supply? AC power might cause that sort of thing to happen, but I'm not sure.

Check your metal surface with a multimeter to be sure that it is conductive across the areas you are trying to etch. If there is a film or varnish, then it will not be conductive on the surface.

Very strange indeed! Please let us know what you find.
pirobot6681 month ago

Low current density [amps per square inch of etch] has the biggest effect on etch 'finish'.

High current tends to smoother, more polished look. Consider a using a nylon paint-brush and wire as the cathode, and 'paint' small areas of the anode to polish.

Low current tends to pit, reveal metal 'grain'. Will give a frosted 'acid burnt' look. Great surface for accepting paint or adhesives. Lots of 'tooth'.

A really great looking effect is to use low current to 'frost' your piece all over, then selectively use high current for shiny high-lights.

DeepakS171 month ago

Hi, Can we use Laptop charging adapter giving output 20V, 5amps as a etching instrument?

Do you have a suggestion as to specific type of vinyl to use? In researching online, there is a lot of variety ... all the way from hobby vinyl to outdoor sign quality. I want to make sure I get a vinyl that's sticky enough. Thanks!

Hi Tori,

I usually use the cheapest vinyl handy (like Oracal 530) for such purposes and it works well.

A little hint: usually I solder the lead to the matal plate, therefore it is quite hot after that. While it's still warm (you might call it hot because I am a jeweler so I sense heat less than others) I give the surface a fast degreasing cleaning and apply the vinyl immidiately. Perhaps you can heat up the plate with a heat gun from the backside after the vinyl is applied.

Btw I place the plate vertically ito the bath and agitate the solution with compressed air through a foamstone (usually used in fishtanks).

CR9Designs2 months ago
I have a smart battery charger. My work-around is a small 12v DC power supply from radio shack. I attached clips to the ends of the wires on the power supply and leave them clipped to the appropriate larger clips that come from the battery charger. I plug in the charger and the converter and it works. The battery charger senses the 12 volts from the small power supply and thinks it's a battery. Cheaper and probably better than placing a motorcycle battery into the system.
Hi. I really want a help. What is the machine that makes the print in metal plates? I want to create my own plates. One example is the image below.
The plates are for nail stamping.
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TechShopJim (author)  karlla.vieira.smart3 months ago

Hi Karlla...

I'm not sure I'm understanding your question, but for this project you would probably want to use a laser cutter to remove the coating on your metal where you want to etch.

If you are stamping on fingernails with nail polish or paint, you might consider using rubber stamp material. You could laser engrave the rubber to create the stamps.

Good luck!
The stamping plates are not in rubber material, they are engrave on steel.

I questioned a company that has some machine. I'lI see what they will tell me.

Thank you so much.
agguilar4 months ago
Hi will this charger work ?
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TechShopJim (author)  agguilar4 months ago

Hi Agguilar...

Probably not. Smart charges and automatic chargers tend to try to make sure a battery is attached. Your electro-etching set up probably won't look like a battery to the charger.

However, the good news is that you can connect this charger to a car or motorcycle battery, then run wires off the battery to your rig. The charger SHOULD charge the battery while the etching is taking place.

Good luck!
Virosa11 year ago

Are there any special steps for getting rid of the salt water (now with lots of metal in it) once you are done?

Are there any environment or health concerns with doing this to aluminum?

Thanks!

rival1 Virosa18 months ago

Yeah, same question. Is the copper in the solution harmful to marine life? How did you dispose of the solution and the sludge? Is it safe (and legal) to just throw it down the drain? How did you check?

TechShopJim (author)  rival18 months ago

Hello Virosa1 and Rival1...

Concerns about pouring copper solutions down the drain come up frequently on Instructables that involve etching PCBs or other forms of copper and brass.

I would like to try to clear the air a little bit here.

First of all, we are NOT dumping the waste copper solutions into the waterways or storm drains or oceans! Instead, we are disposing of these copper solutions properly into the municipal sewer system. There is no marine life in the sewer system (at least not that we care about). Please let us not confuse the two water systems. They are completely separated.

Secondly, if you do a search for "copper root drain" (without the quote marks), you will discover that there are a wide variety of products sold worldwide including in every state in the US which contain copper (typically copper sulfate), and are specifically intended to be legally poured down the drain, either in your sink, or into your toilet.

If copper solutions are dangerous to marine life when they are introduced into the sewer system, and illegal to pour down the drain, don't you think that these root killer products would be banned? (Copper sulfate root killer is actually banned for sale in the San Francisco Bay Area in areas directly adjacent to the bay itself, but it is legal to use in drains, and there is no scientific reason for the ban...it is supposed to eliminate direct spills into the bay.)

So let's all understand that it is perfectly safe and legal to flush solutions of copper down the drain as long as your drain is connected to the municipal sewer system.
athens2rome11 months ago

What if I want to do bigger quantities in one go? I want to etch some pieces of stainless steel that are 4x4 cm each, and I want to etch 20 of them in one go. Sure i'm going to need a big enough tank but would I need higher voltage and more time in the bath? I read in the comments it took you about 2 hours in the bath to etch that plate, would that mean that for my quantity it takes 8 hours or smth? I also want a clean etch as possible, the longer you leave it probably the blurrier the bite gets...
Great instructable btw!

TechShopJim (author)  athens2rome11 months ago

HI Athens2Rome...

Wow, I'm not sure. I think the current requirement would go up, so whatever the current is that is needed for 1 of the pieces would need to be multiplied by 20. You don;t need to worry about the voltage...it can be the same.

So you would wire the POSITIVE terminal from your power supply to each of the pieces, then connect the NEGATIVE terminal from your power supply to the sacrificial piece of scrap metal.

Time should be the same as for 1 piece as long as the volts and amps to each piece is the same.

Good luck...please post pix!
madmikeee3 years ago
This is VERY similar to removing rust using electrolysis, know this, this process gives off gasses, IE in the removing rust off of iron/steel it will give off Hydrogen, HIGHLY explosive so should NOT be done inside. If you use Stainless Steel you are releasing Chromates which are HIGHLY posionous. See here. http://antique-engines.com/stainless-steel-electrodes.htm. PLEASE be CAREFUL and educate yourselves BEFORE taking on these projects, and I would ask those who post instructables to disclose safety items like this so someone who may not know any better doesn't and up blowing up their house/shop or poisoning themselves

I have also noticed ALOT of pimping of Tech Shop lately here on instructables. As great as it is it seems even the most basic projects that don't even NEED a full shop now have to be tagged "Done at TECH SHOP!" I hope the site doesn't start becoming nothing more than a TechShop advertising campaign.
Le Boeuf madmikeee12 months ago

Sorry about the 'post of the living dead', but I would really like to know what alternative electrode material would work well ( etching aluminium ) without producing these hexavalent chromates or other toxins?

Can anyone enlighten me?

TechShopJim (author)  Le Boeuf12 months ago

Hi Le Boeuf...

The link that MadMikee posted has information about proper disposal of the resulting electrolyte. Here is what it says: "If you need to dispose of it, allow it to evaporate into powders and dispose of the powders in sealed containers during your local "hazardous waste clean-up days"."

A little bit of the cathode (the negatively-charged metal) does get consumed in the process, but not in any amount you could ever measure. The material that is removed and ends up in your salt water is the metal you are trying to etch, which is the anode (the positively-charged metal). So in the case of my Instructable, you are ending up with brass (copper and zinc) in the water, not stainless steel.

You can use any metal or conductive material for the cathode. You could probably even use graphite.

Good luck, and have safe fun! (And thanks to MadMikee!)
TechShopJim (author)  madmikeee12 months ago
Hi MadMikee...

As stated in the very page that you link concerning using stainless steel in this process, talking about the resulting salt water electrolyte: "If you need to dispose of it, allow it to evaporate into powders and dispose of the powders in sealed containers during your local 'hazardous waste clean-up days'."

That' great advise that everyone should heed! Thank you for posting that link.

As to your comment about the huge number of TechShop member posts on Instructables, we have a very close relationship with Autodesk (the owners of Instructables) and Instructables themselves. TechShop has over 6,500 active members across our 8 locations so far, and we actively encourage our members to participate in the Instructables community and share their knowledge by their posting Instructables projects.

For the record, I did this Instructable at TechShop San Francisco! ;)

Thanks!
TechShopJim (author)  madmikeee3 years ago

Hi MadMikee...

I have noticed the number of Instructables tagged with "techshop" increasing a lot over the last year too.

I think the reason you are seeing a lot of "pimping" as you refer to it for TechShop is that A.) TechShop is just a really cool place to make things and our members and staff like to talk about it, and B.) We STRONGLY encourage our members and our staff at all 5 of our TechShop locations (Menlo Park CA, Raleigh Durham NC, San Francisco CA, San Jose CA, Detroit MI) to document every single one of their projects on Instructables. We believe in the concept of Instructables and we believe in sharing ideas.

We have almost 3,500 active paying members right now across all our locations, and when that many people are encouraged to write Instructables, you are going to see a lot get posted here.

Where do you live? Do we have a TechShop near you yet?

Thanks.
Alcyon2 years ago
Hello Jim, what about laserprint tranfer method.?
TechShopJim (author)  Alcyon2 years ago
That's the method I used for this. I really want to write up an Instructable for the exact process I use because it works extremely well. I use an ancient HP 1100 laser printer to print the pattern on to a special paper that is coated with dextrin, and then I run the copper clad board with the dextrin paper face down in the board through a hot laminating machine for perfect and even transfer every time. All you have to do with the dextrin paper is let water touch it, and it releases and leaves the toner behind on the board. There are other Instructables on the general toner transfer method, so you might want to look at those.

I'm also developing a method that uses PMMA dental acrylic powder and monomer to create a thin layer of resist that can be cleanly and completely removed with a laser cutter to expose the areas to be etched away. Spray paints and other finishes I have tried, and I've tried every one I can get my hands on, tend to leave a waterproof film in the lasered areas that must be cleaned with isopropyl, but this step often disturbs the paint covering the traces.

Don't forget that there are better electrolytes for nonferrous metals; and a different solution will make a difference as well. Drop some copper in 5:1 acetic acid/H202; you'll see a difference quickly. What we're really doing here is speeding up the oxidation process, I would surmise.

katylorj1 year ago

I am baffled as to why my copper is not etching... no bubbles at all! I'm using a charger that can charge a motorcycle, boat, etc... and nothing.

I have my super saturated salt water, copper with art to be etched, copper cathode/sacrificial piece — both attached with copper wire, that then connects to copper clips of the battery... What is going wrong?!?!

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TechShopJim (author)  katylorj1 year ago

Hi katylorj...

There are two things I would try in order to isolate the problem:

1.) Is your copper protected by a thin later of lacquer or plastic? Often, sheets of copper and brass are coated in this way so they do not oxidize, and the coating is really hard to see it. To check for a coating, take any multimeter and switch it to CONTINUITY or OHMS and touch the probes at two points on one face of your metal. If you get a reading, then you're OK...this is not the problem. If nothing changes on your meter, then it is probably coated, in which case you will need to remove the coating with an appropriate method (acetone, sand paper, lacquer thinner, etc.)

2.) Is your battery charger timing out or getting tricked? Some battery charges are "smart", which in my mind means "dumb". Smart chargers electronically check the conditions of the load and try to figure out if it is a battery or not, and if it is a battery, whether the charger should keep charging or not. Your tub of salt water and two pieces of metal may or may not convince your charger that the load is a battery. To check, disconnect your charger from the metal pieces and unplug your charger. Then, plug your charger back in and measure the output when your multimeter set to VOLTS DC. Do you see a voltage of around 14 volts? If you do, then just quickly dunk both of the alligator clips from your charger right in to your salt water. Does either one of them fizz and bubble a little bit?

Let me know what you find, and we'll go from there.

Thanks!
Jobshopper1 year ago
@ hornbadoing I have a sign place I work with that helps tune up my artwork and cuts my vinyl, the cabinet shop mask was twenty bucks for art time and four masks. Cleaning up the artwork was the majority of the cost. I used the vinyl they suggest for paint work masking and found the sign vinyl much better.
Jobshopper1 year ago
I've been playing around with this, aluminum is much faster than copper or brass. It took me between 2 n 3 hers to weed and 25 min to etch the semper phi the copper takes much longer for me anyway..
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guerroloco made it!1 year ago

1st attempt at etching aluminum using this method. Not bad! Needs polishing. I noticed that the terminals of my power supply were getting hot after a few minutes -- it might be a good idea to add a small light bulb or some other load in series to protect the power supply.

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I also used a toner-transfer mask rather than vinyl.

@guerroloco: please explain, what is "toner transfer mask" ? where did you buy it?

TechShopJim (author)  guerroloco1 year ago

Hi Guerroloco...

That looks great! Thanks for sharing the photo!

How did you do your toner transfer method to such a thick piece of metal?

The aluminum sheet is not especially thick, maybe .025". Toner transfer is easier for me, since I have access to a laser printer but not a vinyl cutter. Here's my rig. There's a motorcycle headlight in series to lower the current from around 15 amps to about 3.

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