How To Cut Steel With Electrolysis [Experiment In Progress] - NightHawkInLight
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- Опубликовано: 8 июл 2024
- Cutting steel with electricity and water. I've been playing with how to this method for the past few weeks and am having some trouble, but I know it's possible.
Check out this video to see where I got my inspiration: • How to make reedvalves...
I tried this same method at one point a few years ago and had better results than I have so far been able to replicate in my latest experiments. Possible causes that I'm considering:
1. The metal etching paint formula has been changed
2. Paint requires a longer time to cure
3. Baking soda is not an acceptable replacement for salt (I used baking soda in these latest tests because it does not produce chlorine gas as NaCl does)
Let me know what you think in the comments below!
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SO.. I've got a bachelor's in chemistry. Briefly, I can see several things.
Firstly, Carbonates are bad for this. Bicarbonates are also bad for this. If you're intent on using a basic pH use borax (sodium tetraborate). It won't vent carbon dioxide if there's a rapid pH swing, it is basic, and is a good buffering agent.
Secondly, I would probably try to use an acidic environment for this. Acids are easier to work with if you're trying to etch/eat metals because they tend to make the solution more acidic anyway as they dissolve into solution. In theory, by making the solution acidic to start out, you slow down this rate of dissolution. In practice it largely depends on which anion is generated by the acid.
Vinegar is very mild. More aggressive is phosphoric acid, which is the workhorse of CLR (a domestically available solution in the USA). Hydrochloric and sulfuric acid are aggressive enough to eat the steel without any electricity.
Thirdly, we come to electrode materials. The flexible pipe is not regular steel. It's stainless steel mesh. It's probably nice to work with because of the surface area, but the chrome will interfere with the other piece of metal. I'd switch over to one of two materials: Steel wool or graphite.
Steel wool should be similar to the sheet metal's composition to be ok, and graphite pushes in the other direction entirely (if there's a side reaction, the carbon oxidizes and goes out of solution).
Finally... I think going with Wax is probably best, but it's worth noting why. The wax, especially if you apply it hot, sticks directly to the metal. Most paint does not. Paint kinda just sticks to it's self. You could use vaseline, but wax is probably best because it's a bit sturdier. Alternatively, you could use an adhesive... but the carving of the design becomes tedious at that point.
Walter Bunn +
Ye good ideas, I try to make sure this message is visible by adding comments.
=)
Walter Bunn pfft nerd!
I can dig it
Walter Bunn yeah that's what I was telling his as well
Ah I tried this while I was making my time travel invitations! I was never able to get a very deep "cut" before the wax peeled away so I ended up switching to a casting method. I guess thats the same problem you are having. Perhaps go slower? a lower voltage that doesn't make so many hydrogen bubbles? Guess I'm not much help but I am interested in learning the answer this could help make some rocket parts that I want to build.
+MrJimbo1qaz Maybe he is just upside down in it...
+MrJimbo1qaz why is yours inverted?
Cody whens the next bee video going to be up? Love watching those little guys at work
dude....i love you....and your videos.....
He had not enough with cyanide
NurdRage might know something. He's a RUclips chemist that does videos similar to yours.
try bitumen or tar(katran)
NileRed is also nice
Cody from Cody's Lab is also a genius with metals.
Or Cody
MarklenIngyer or Mike Cthulu who makes swords and does other metallurgy projects.
Using standard Sodium Chloride will produce lots of Chlorine gas which Will rust the metal more than etch it. Sodium Bicarbonate is better although it'll also release CO2 gas.
Those excess gases might be adding to those bubbles that keep forming under the paint. I'd recommend Potassium Carbonate as your electrolyte, or if you don't have any you can decompose Sodium Bicarbonate in Sodium Carbonate by throwing it in an oven for awhile which is a good alternative.
Also maybe Lower amperage or a smaller Cathode could cause less gas to form on the Steal leading to less issues.
You could also try using an etching solution made of Vinegar, Salt and Hydrogen Peroxide. It has worked well for me in the past and when heated can go quite quick.
You can avoid the Chlorine production by using a dilute salt solution. A dilute solution would enable electricity to be conducted but only allowing the electrolysis of water. To avoid this whole issue, a sulfate could be used. Sulfate ions would not de-ionise without decomposing.
Another way to completely avoid gas production at the anode is to use pure iron. But I don't think he's interested in that.
When I use electrolysis for removing rust from old parts I use washing soda, which upon further inspection is Sodium Carbonate. Not only is there no chlorine gas from this I think it does better than baking soda for removing rust. I know because I used to use baking soda before I found out about the chlorine gas, so I've seen both strip rust and I think washing soda visually does a better job.
Sodium Carbonate works great and is easy to make, also Julian why does pure iron not form gas? I ask because though I may know a bit about electrolysis I haven't heard that before.
Hello. I made a rust removal tank using the same principles. I experimented with different solutions and found that if you use distilled malt vinegar and table salt you can get a very aggressive etching solution.
Also in my years as an electronics engineer we used to etch prototype pcb's. The line you score in the primer wants the be one third the thickness of the final line required as the etching will always cut under your dialectic cover coat. This, depending on the thickness of material, may need to be thinner. You need very little metal exposed for the electrolysis to work. Hope that helps. I may try a spot of experimentation myself now you've got me thinking about it :)
I have some ideas to try chemical etching in place of the electrolysis myself.
Your problem is the use of baking soda. Etch Primers use an acid to form a physical and chemical bond to the metal. Seeing that the baking soda is a base, you are breaking that bond the paint has with the metal.
Try using Kosher or Rock Salt (table salt in the US also has iodide), in a well ventilated area.
If concerned with Chlorine gas, try using Ferrous/Iron Sulfate or Copper Sulfate (both Gardening Supplies, Ferrous Sulfate as a soil supplement, Copper Sulfate as a pond algicide). They will smell bad, but no chlorine.
Wow, I feel like an idiot for not connecting that a bicarbonate my not mesh well with an acidic paint. I figured most of the acid would be gone post drying but it wouldn't take much to cause bubbles. Good thoughts.
Kind of a waste of copper, and not so green to make a big mess with that and dump it all down the drain. If it's lower pH you want, you might try using vinegar.
Once you get rid of the bubbles, you'll also want your metal to be etched smoothly. That is, you need an electrolyte where the iron is fully soluble (to avoid getting deposits forming on the metal surface as it is being etched), and that is relatively viscous. Also, avoid chlorides : I heard they accentuate pitting.
Phosphoric acid (which can be bought in hardware stores as rust remover) should be ideal, though costly. Sulfuric acid might be a chaper alternative (the 37% aqueous battery acid, not the concentrated oleum!).
Some sodas like coca-cola or pepsi might be a more "ghetto" way of getting a dilute solution of phosphoric acid. THough be sure to boil them beforehand to degas all that CO2.
Adding vinegar to a koser/rock salt solution is not a bad idea. However a mixture of just Vinegar and water would not make a good etching solution. For a good etching the water needs to be filled with free ions to allow for electrical conductivity. Hence why 'salts' are used. Vinegar is an organic acid and produces very few free ions to conduct electricity, but would lower the pH of the solution.
Natriumpersulfat or iron perchlorate used to etch PCBs would not work on it? If not, why?
I have a hypothesis: Electrolytic etching might not be possible to use as cutting method, reliably at least, especially on thicker materials. Once the cut reaches sufficient depth the electrolytic etching will be omnidirectional and work it's way under any coating no matter what. I don't think there's a way to control electrolytic etching in a unidirectional manner. All other cutting methods are unidirectional, be it plasma, water jet, or old fashion mechanical cutting with a blade.
Does that make sense? Once the electrolysis has eaten a shallow trough in the metal it will also attack at the sides of the cut without having a barrier that grows with the cut and follows it through the metal.
Maybe I'm way off base here, but that's what I'm thinking.
I was about to say. After clearing the surface with such a thick piece, you gained enough surface area to start eating at the metal under the paint thus screwing up your etching. In the source video, the gauge metal the guy was using was very thin.
Maybe if he took the plate out every 12 hours and cleaned it, then reapplied the paint and rescratched the plate accommodating for loss of mass on the finished design, he might etch it the way he wants, but at that point he'd be better off using an actual laser cutter. This is one of those ideas that only works based on scare/volume of material.
Yes. It seemed blindingly obvious to me right from the start. Its '3D', not '2D'.
It's Impossible to get there without an undercut. If coming from both sides (top and bottom) it will meet at the middle of thickness as a knives edge. That knives edge would be the ideal diameter of the design, from there on up to the top and bottom surfaces it gradually increases eating away metal with the greatest amounts removed at both the very top and very bottom of the flat surface.
Joe Brown, how to dissolve the anode quickly mate, Im doing fun experiment.
hey Hawk, ive been subscribed since i was 12, and i turned 16 yesterday and I just thought about how far I have come in my life and seeing this, i realise how far your channel has come within my last 4 years here, you give us great quality videos, great ideas and an overall fun time. Always excited to see your videos, Thank you
Hey happy birthday!
Nice video! Also great to see YT channels like my own that give credit to others for an idea shown.
AHH! I'VE SPENT THE LAST HALF HOUR TRYING TO FIGURE THIS OUT. Don't use baking soda*!!!!* When you electrify the water, the soda breaks down into Oxygen and other bits (not exactly sure what), Making the Oxygen bind immediately to the Iron since it is becoming a Negative 3 ion (because you have the iron as the Anthode, and the Oxygen wants to get rid of its electrons). Making it quickly form into rust because your Cathode is most likely Iron tubing of some sort, so you're basically doing Oxygen Electroplating instead of Sodium electroplating. In your Inspiration video, He use Sodium Chloride _specifically_ to avoid the rusting. Think of this entire Electrolysis experiment like Electroplating, Except you're trying to make the Iron into a weaker Crystalline, not any random form because it will bind unevenly. As seen from using the Baking soda. Using Salt should make the whole experiment smoother. Any electrolyte that contains Oxygen is going to ruin your experiment. Let me know how it turns out :)
Very good point. Use something which makes the oxidised iron water soluble.
Then: Would adding peroxides or using HCl instead of NaCl/Carbonate be better?
When playing with Cl and electrolysis, be aware that any metal in the same room will rust.
Using any Peroxides would give the same rust problem. Oxygen being a non-metal will do whatever it wants to get to a more stable spot (Thus creating bubbles under the paint). The reason that Salt (NaCl) worked is because it isn't actually binding to the iron in the steel. You're trying to bind the elements to the Carbon, making the Steel structure weaker. That is why the cuts where able to be so thin in the inspiration video, and also why the waste was Crystalline, not rustic. You can't use anything with Oxygen because it creates polar products (such as Water). Carbon on the other hand is structured evenly to allow for crystalline structures. So is Silicone. The crystals that you're trying to form is to literally create a glass complex. Have you tried to bend glass back and forth? It cracks because of the micro layering being uneven. With Electrolysis, You can make specific points where the crystals won't want to move, causing them to snap off. If you wanted to corrode the material away, Why would you even want to use electrolysis. It takes way more power to run electrolysis through this setup where you could just have the steel plate sit in a strong acid. *Especially* if you're trying to cut thick steel, Don't waste time with electrolysis. Get down to the point, you want an acid bath. Then you can use the Baking Soda to neutralize the acid when you're done. No car batteries needed.
another RUclipsr uses this method to etch steel but he uses self adhesive vinyl to protect the pieces he doesn't want exposed and it works really well for him
This sounds very much like the techniques used in etching PCB's. There, the trick is to get the etching done in a relatively short period of time, so that there is not enough time for the etchant to eat away at the metal through the walls of the cut, which can sometimes result in having the mask flake off.
I think since you are using electricity instead of acid, that you could also improve the quality of the cut by being more directional. Maybe ground the metal, place it flat in a basin of electrolyte, and use a small relatively pointy positive electrode to get close to the parts of the metal you want to cut.
Since speed of cut is probably an issue here, You will want to ensure you have a high current supply available, something like a car battery, or at least a supply capable of supplying several amps. That way, you can add plenty of baking soda, or acid to the solution and know that you aren't being limited by the power supply.
Finally, combining the effects of electrolytic corrosion with a chemical etchant may further improve results. As a starting test, I would recommend equal parts vinegar and 3% hydrogen peroxide, since that is readily available, and surprisingly potent.
Good luck, this looks like a very interesting project!!
Its because of undercut, as the cut gets deeper the sides are exposed even though they were originally protected by the paint which are then eroded perhaps try some thinner steel
AM I THE ONLY PERSON WHO THINKS HIS VOICE DOESN'T MATCH HIS FACE?
Illuminati ;)
You are.
nope
nope, no offence to the guy but it sounds like im listening to a crappy tv commecial, im sure he doesnt speak like that when not filming though.
I'm sure that just like The Elemental Maker and that Theranos chick, he's putting on a much deeper "presenter" voice.
have u guys seen his thumb it is so small as in his NAIL
Try using an acidic electrolyte, such as sulphuric acid, hydrochloric acid or ferric chloride. Alkaline conditions might be causing dissolved iron to immediate precipitate, blocking further attack. Phosphoric acid should not be used for similar reasons.
Interesting, that very well could be
Caustic Potash - It's often recommended for HHO generators
Edit: if you want/need some, PM me. I have a full container I don't want
I've been working on a project similar to this but instead of using electrolytes I been using Photolithography and acids. By using positive developer (sodium hydroxide), and a UV photoresist paint that hardens in the present of UV light. I been trying to etch detailed images into metal plates. this could be adopted for you purpose.
Steve D
Use caution, some acids attack steel.
Hey Ben, I tried this and I used NaCl for my electrolyte
also I dipped my steel plate in wax then scored it and pumped 4v 1amp through the steel using iron wire as a second electrode and I was able to cut right through the steel.
Just don't leave it in there for too long that causes the messy cut that you showed here.
I left mine in there for about 3 - 5 hours, that etched it deep enough to have the steel hanging from a thin piece of iron foil which I was able to just cut away with a knife.
I hope this helps, also try using a stronger electrolyte ex. instead of bases try acids like HCl. This worked 10x better. Also if you don't want that rust coating the steel try using NaOH this will actually dissolve the rust, but it wont dissolve steel. It'll clean the steel giving you a nice and shiny surface.
Glad you had some success! Thanks for the report. I'll be trying NaCL again and a few new things this next week
NightHawkInLight what I remember from Chem is that redox reactions depend on the materials of your anode and cathode. So, with an anode of steel (iron) go for a cathode that is a better reducer like Aluminum in an HCl electrolyte. Not sure how well my 10yr old memory from classes and 30second of refresher google searches will apply to real world electrolysis cutting, but I
hope it's going better!
I tried this again this time with thicker steel, one thing that I saw was some carbon coming out of the steel. this must have been because steel contains carbon. The first time I tried this I used an iron plate, Im thinking the carbon bothers the electrolysis process, I dont know why but it seems like it does. the first time I tried this I used 1mm thick iron which took about 4 hours, this time when I used 3mm thick steel I thought I would take about 12 hours, instead it took about 36 hours so there is a huge difference between iron and steel.
I hope this also helps you :)
Good luck.
I'd like to see how well this can work.
maybe its to thick
or is it
That's what I thought.
That's what she said.
+balisticsquirel I applaud you.
then.... MORE CURRENT!
I have some experience with this, though not for cutting, I make and etch my own logo's and I can get very detailed and good depth. I have not tried going completely through metal with my method but think it would work.
I use Press N Peel PCB etch resist. It comes in sheets that you print onto with a laser printer, you then use heat from an iron to transfer the print to the steel and peel the backing off. It think it's worth trying.
Looks like AvE covered it, once it starts you have it dissolving in all directions, not just straight down. Thing like you're digging a hole in the ground, once you start digging you're not just exposing ground right below you, you're also exposing dirt to the side of you. If you were forced to dig at any dirt you see starting with a grass covered lawn and a small patch of dirt, you'd quickly be digging a half-sphere growing in diameter, starting right at the boundary between the grass and the dirt.
you need something to mix the solution, a recycling pump is the easiest method, because during electrolysis, the solution near the electrodes have an higher concentration on salt then the rest of the solution, either you need a specific voltage to avoid unwanted reaction (see the standard electrode potential table), higher current mean only faster reaction (maybe it will change the edge of the cutted piece)
Interesting thought.
maybe you shouldn't use the plate itself as an anode, because the current flows from water and skidmarks you made in all directions. I would try putting two plates (isolated from salty water) on both sides of the steel sheet, which has your scratches on both its sides. this way current will flow through the plate perpendicular to it and not go under the paint/wax/whatever
I would try thinner stock, does the spring steel video show the thickness?
a couple of theoretical suggestions ^^ I don't know if you already tried it, but Sodium hydroxide (NaOH) is a very good electrolyte. Also, Have you tried experimenting with the orientation of the metal sheets ? Maybe laying them flat would help.. And finally, have you tried to sand the metal sheet down with sandpaper ? That could help the paint to stick ^^
Hey NightHawkInLight, before you read all of this i have no solution at all for your problem but i do want to point out that i find it a great idea to involve your subscribers into your projects! Keep up the amazing work.
Thanks!
NightHawkInLight Out of curiosity once the cut is made what is to prevent the electricity from continuing on to the now exposed metal? Anyway, awesome video; great work.
It will continue on if you let it.
What if you tried this using just alum to dissolve the steel? removing electrolysis from the equation
how
what happened to the sodium metal production? I was really enjoying that as a chemist.
The videos took a lot of time and weren't getting enough views to pay for the supplies...
NightHawkInLight that's a sad shame. also, for this project I really suggest you look into a chemical called ferrous sulfate or iron sulfate. it's used for etching and is cheap at www.unitednuclear.com. I don't believe it will make iron oxide like you have made because it won't cause an oxydation reaction because of the electrolysis. also, try galvanizing your steel. that will further help with the rust. best of luck man
that was really cool
Suupare Truckerz I know right? I'm thinking about continuing it on my channel via the industrial way instead of a thermiteish reaction.
Perhaps you should talk with AvE - another RUclips creator, because he is developing a desktop EDM from a 3D printer. Since EDM uses electricity to remove or erode metal in a very controlled manner this may be helpful or at least something you would find interesting.
Peace!
He was already here earlier
Cool!
I'd be concerned that the "path" of the cut won't be linear through the sheet as more and more of the base metal is removed, there is a greater surface area of the "thickness" of the sheet to be attacked.
You're correct. When working properly this method will cut the metal with an expanding half circle so the cut widens at a 2:1 ratio to how deeply it cuts. The thicker the metal the bigger that half circle will get before reaching the other side
NightHawkInLight If you can work out the bugs with the electrolyte and paint, though, this looks promising for prototyping.
Did you try putting the etch on each side?
That might make a difference
woa cool. cmon internet you can solve this.
I don't understand why the removal of material would continue in the direction through the metal, instead of trailing off in other directions once the initial surface has been broken. I think the thin spring steel works because it is so extremely thin that any etching that is coplanar to the surface is negligible because it doesn't have time to gain any real distance before the material is cut all the way through. The tolerance to the original etch marking is probably some ratio to the thickness of material. Thicker material, the further it will start to etch and propagate "under" the primer.
With proper paint adhesion the cut should propagate in a half circle through the material, growing wider in 2:1 proportion to it's depth.
Are you following the technique outlined in the video you linked exactly
? if so , have you also tried without the current limiting bulbs ?
I find it totally refreshing that you would post a video of a "failed" experiment. To many people create a persona of being perfect or an expert in everything and so when someone like me tries something and fails I feel like I'm the only one.
One I failed at was a hydro generator. Anyway kudos to you for being honest. I am gonna subscribe and check out more of your stuff.
My grandfather used to do this in his workshop. Making elaborate tinker toys, ultimately igniting my Rube Goldberg machine obsession.
After seeing your I asked anyone who would remember and no one can remember remember the specifics but I both think auto primer was used, but there may have been a auto sealant as well- given it was a body shop. And etched off on both sides- I do remember that because I was the labor 😉.
It was great fun as a kid, and I found your channel trying to remember how it was done.
Good luck and if I have success with auto primer and sealant I will let you know.
Here's a few free ideas to consider:
1. Not sure if it was just for effect on the video, but your tank solution looked pretty dense with rust from the process, maybe change out the fluid more frequently during etch runs. All that extra iron oxide might be changing the fluid's electrical resistance or electrolytic makeup enough to negatively affect the electrolysis efficiency.
2. Instead of scratching away the resist coating (which could be lifting the etch resist at your tool marks) try creating an adhesive stencil that you can paint over and then peel away before the resist cures. There's plenty of consumer cnc-type cutters that will work on vinyl sticker sheets, Cricut is one brand that comes to mind.
2a. Bonus points if you can also line up a mirror image stencil on the back side to etch from both sides at once.
2b. Double bonus if the vinyl itself survives the electrolyte solution, then you can use it as a primary resist instead of a paint mask.
I, too saw the video and saw great possibilities. After reading the suggestions I conducted the following: After cleaning a 10 inch circular saw blade with denatured alcohol, I coated one side with 5 minutes epoxy. This was followed with 4 thin coats of etching primer and topped with four thin coats of polyurethane. In 5 quarts of water, I added one cup of sea salt. For the negative side, I used some 12 feet of rolled up 18 gauge copper wire. After 18 hours, a quarter size bubbling appeared near the test line. After 36 hours, the bubble area was the same size. After 48 hours I scraped off the epoxy. I removed more metal scribing the line than 48 hours in the electrical charged solution. Electrolysis metal removal had been known for centuries. If this was a feasible steel metal cutting process, it would already be common place. The metal may be too hard and require annealing. Using 15 or 30 minutes epoxy would be better. 5 minutes epoxy sets up too fast and makes for poor surface coverage. With epoxy, adding the etching primer and poly may not be necessary. I also noticed the back side with only the primer and poly did not show any bubbling. Try turning the scribe side away from the negative anode.
Your videos are some of the best on RUclips. Top notch, keep up the good work
Can you show us a tour of your shop, and how you keep it organized?
thank gawd, all the videos that make it look so easy to just use a mask of nail polish for a great etch i was beginning to think it was just me that couldn't get a painted mask to stick when submerged regardless of how good the prep was!!!
Consider dipping the plate into a solution of 20% phosphoric acid, 80% denatured alcohol. Dip the plate in for an hour, then remove and let air dry 2-3 times. This will convert the surface of the metal to iron phosphate which will not only help the paint stick, but give an additional bonding layer of protection.
For a cutting agent, Potassium Hydroxide (potash) might be better than baking soda. Hopefully this helps. I am a big fan of your channel and wish you luck.
I would say it's a win already. You just gave me a great idea for a surface finish for plates to go on a Dungeons and Dragons prop I've been designing for a while. :-)
I really like the ideas you are coming up with. Like making a cold stone. I have never seen any other RUclipsr do that before. I really enjoy your videos. Thanks for making them :)
your committment to the fans will shine through youtube in a big way someday my friend.
Like many others have already commented, the problem you're faced with is known as undercut in the semiconductor industry. With wet processes you will inevitably encounter unwanted etching because the corrosion propagates through the metal, not just where you have tapered off. Your idea may only work for extremely thin metals, and even then the error associated with it may be significant. But do keep at it, you might just find something useful along the way!
I know this is going to sound low tech compared to some other suggestions, but the thickness of your material makes a lot of difference. As the steel is worn down, think of it like a burning a candle. The taller the candle's relation to it's diameter the less even the sides will melt and it will not be uniform along the side walls. If you have a thick sheet of steel relative to the width of your etch, then the electrolysis will begin to infiltrate into the side walls of the etched surface before it's penetrated through. I've seen etchings of copper plate for PCB's be completely ruined because of this. It's not actually getting through or even really under the etching paint or wax. It's going through the side of the freshly etched surface and getting under the paint that way moving laterally through the material rather than through it. Try every so often scuffing it up and cleaning the surface, then reapply the etching paint and scoring new etch lines into the surface. An alternative could also be to use etching pens that would allow you to do touch ups along the sides as you go to prevent the sides of the material from being bleed into. It really has little to do with your electrolyte or the voltage as much as it does the relative thickness of the material to the width of the etching area.
One of my favorite channels
note that excessive current will result in more power being spent on electrolysis of the water instead of on dissolution of the iron. At lower currents, almost no bubbles of gas are created at the anode, making it less likely for bubbles to "scrub away" under the paint
Always use considerable agitation to keep the metal exposed to the solution for deeper, faster, cleaner cuts. Use same area plates as parallel to target when possible for even cutting (think path of least resistance). Use several coats of enamel. There will be undercut on thicker targets...so allow for this and finish the piece later. Don"t give up on this process...it is the most overlooked tool/process in the shop! It requires an appropriate electrolyte for the type of metal being cut.
Good luck, love your vids.
FWIW, I was experimenting with electroetchig metal as a kid over twenty years ago, and the best result (very clean deep and hair thin lines) I got by coating it with a mixture of white parafine, asphalt and pine/spruce resin mixed 1:1:1 by volume, boiled together and cooled in water. It resulted in a substance that was wery sticky when warm, with low melting point, and relatively hard but not chiping when cold. It was wery easy to make thin coating and then scratch the design with needle. Unfortuntately the substance had also rather, ahem, excremental brown color.
I have not tried to cut all the way throught the metal and as etchant I used saturated NaCl solution.
this would be extremely helpful for lots of projects. hope you figure it out!
I etch PCBs by covering them in spray paint, laser engraving the paint away, then using an etchant that eats away the copper (copper chloride / ferrous chloride / hydrochloric acid + peroxide). The reaction needs to be fairly quick or else the paint eventually curls and peels and your etch goes outside the lines. I imagine it's a similar problem when using electrolysis. You probably just need a find a resist that is durable enough to withstand prolonged periods of electrolysis. Have you tried a UV curing paint? I believe that's what's used as a solder mask in commercial PCB production and is generally quite durable.
I do that with copper and zinc , it works great with zinc . What I do is I coat the metal with beeswax (more flexible than parafin or palm wax and perfect for this) then I take an awl or a knife to scrime my patern onto the wax until the metal shows up , than I clamp the metal with a part with no beeswax to the positive terminal of my generator and use another plate of metal in the negative terminal . I use white vinegar as electrolyte , I don't think baking soda is up to the task , the best thing to use is NaOH .
Also beware of stainless steel , if it dosen't oxydize in air it will be more difficult to oxydize it with elextricity , also the wider the grove to cut is , the harder it is to cut because you have to oxydize more material , so try to make the finest line possible , you cannot really use sticky tapee because I didn't found this very effective , I try paint , but I'm not happy with the result , beeswax's the best
In semiconductor fabrication they do alternating rounds of etching and passivation to control the angle of the cut, if you just etch it goes everywhere or starts getting below the mask like in your paint bubbles. So short version: paint, expose, short etch, clean, repaint, expose, short etch.
Once you get into the metal the electrolyisis can attack the newly exposed metal on the sides of the cut and go horizontally. The only surefire way I can see to avoid this would be to constantly take the piece out and reapply the paint. This would drastically increase the time it takes and would still probably limit how complex you could make the shapes. In the times between applications it'll still eat away the sides just a little bit, and since that will stack over time any really intricate shapes will be lost.
8 years ago when I was a student
I was doing experiments with emh machinery
and I made the most precise things when I used a thin self-adhesive tape
something like a thin film strip
My grandson uses vinyl he had a friend cut some vinyl stencil out and used vinegar electrolysis on aluminum and it worked great
I've played with this a bit and have found a few things that may help you. Firstly, use salt instead of baking powder. It won't soften the paint as much and be sure to fully saturate the solution so it pulls more power (you may need to use a battery instead of a charger). The second thing is to use a flat secondary electrode (the same size or larger as the plate you are etching) and get it close to the surface you are trying to etch. I used plastic standoffs which kept it about a half inch away from the etching surface. This will greatly speed up the process and gives a much more uniform and consistent etch. That should get you on the right track! Side note: take care if your fingers absorb too much salt water, as it will greatly lower the resistance of your skin and you will conduct even at 12v, enough to light an led in my experiences.
Cheers!
top quality intro and thumbnail
I use a combination of chloride and sulphate salts acidified with hydrochloric acid to etch metal plaques, including stainless steel , under the influence of a DC current. I have tried cutting with the system as well. For cutting you need to register the artwork perfectly on the back and front of the workpiece to etch from both sides. Self adhesive sign vinyl is the best resist.
The positive cable connects to the work piece and a large flat negative plate needs to be on each side of the workpiece.
As etching progresses the exposed metal starts to etch under the resist so , true accuracy is only possible on very thin workpieces. The negative plate proximity is also important for the speed of the reaction but beware, the closer you get the greater the pull on your power supply. I use a 130 amp DC welder to etch plates up to 300 x 400mm and everything gets really hot including the electrolyte solution. Be really careful folks this can really hurt you.
Cool video, I had no idea that something like this was possible. As for why it was not working, I know nothing about electrolysis.
You are doing a very good job. :) Thank you for your videoes
Recently i've been removing rust from some old cast iron pans, and i think you might have your leads connected backwards. In the cast iron videos, they always clip the black (negative) lead to the pot or pan and the red (positive) lead to the scrap or sacrificial iron (they say to stay away from stainless steel and copper). this way, the electricity flows from the pan to the scrap. in the end, the rust, oil, and carbon buildup has been removed from the pan, and the scrap is coated in crud. also, instead of baking soda, they always insist on washing soda, or sodium carbonate (i found mine in the farm supply store by the laundry detergents.) also, i learned that the more scrap i had surrounding the piece, the faster/better the process was.
I've seen this work for the pulse jet reed valves. I think it works for that because the material is so thin (0.010-0.015") The thicker metal you're showing would allow the erosion to work sideways. Also, if you're having "bubble" issues, try using an aquarium pump or something to stir the water around so the bubbles free from the surface and wont prevent the liquid from contacting the surface. Good luck, hope it works out for you.
two ideas:
1. powder coating maybe
2. lowering the voltage -> in my experiments, only the high-voltage-induced aggressive bubbling destroyed the layer
i did etch very fine typo into metal so the etching was done in minutes. I think everything is different in a long-term application like this. I had best Results with a matte primer out of everything i had in a spraycan - didnt try wax like you did. I also did my marking in a lasercutter pior to etching.
I have always used vinegar with salt(non iodine) dissolved in it, and to isolate the metal I used black nail polish. I do not know the length of time the polish will stay on before needing a new coat, but its worth a try @Nighthawkinlight
As Gabe Sewell said below one of the main problems is the thickness of your metal. The reason it worked for Bruce in his video is he used a very thin metal so he was able to cut thru before his etch got to wide. You are using a much thicker material so you are going to get erosion away from your masking. This same thing occurs with chemical etching and you have to adjust the size of your masking accordingly or etch a short distance and re-mask the sides before going deeper.
- so far as etching is concerned, the electrolyte shouldn't make much difference. But it might attack the resist coating.
- Undercut proportional to the thickness of the etch should be expected. But more than that would be an adhesion problem. For a really good cleaning I've heard that a strong alkaline solution (like lye) is needed to cut the grease, and any handling with bare hands afterwards can leave skin oil deposits. Alternately, an oil based resist (like wax) shouldn't care as much about oil deposits.
- Hydrogen bubbles will form. As long as they don't adhere they shouldn't be a problem. On the other hand, if bubbles form and adhere they may prevent depth of etching. Same with rust that adheres. Orientation of the metal sheet and agitation of the solution may make a difference.
maybe I missed something in the video but the first thing that stood out to me was your flow. You need both an anode and a cathode. Personally I would submerge the metal in the center of the tank, upright, then have your anode at one end, then your cathode at the other. I've found decent carbon steels work well for this. You can continue to use the baking soda (washing powder variety) if you use two pieces of carbon steel and your water won't get as gunked up.
interestingly enough, this process will also clean the object inserted. Its a method I use for rust removal. Occasionally it has cut steel for basic etching designs I've done. I've never tried anything like completely cutting THROUGH steel, but I'm assuming it should work.
Oh, uh, kinda an important step: Do this shit outside in a well ventilated area.
also to note, I'm not sure if being used directly as your anode is what is causing the bubbling on your paint (though I'm willing to guess current passing through it from beneath the layer will create a bubbled effect where its released) but if it doesn't change with the setup I mentioned, try changing that first. Most etching jobs take only a few minutes. I've seen some groves put into solid steel cylinders that were impressively deep without it causing the metal to rust in minutes.
I could imagine 3d printing a part that covers the parts you don't want eroded and clamping it to the metal sheet could work. A bit like making a tank that only exposes what you want removed.
In simple words, I believe that it's all about the rate in which only the metal part that you want, becomes rust; so the higher the reaction speed is, the better. On the opposite side, a high reaction speed will produce more bubbles in less time, which could lead to bubbling under the paint.
I think there are too many factors that influence the outcome of this experiment, so rather than explaining them, I will propose a method I believe would work and or some observations:
- The metal sheet should be as thin as possible and hopefully not the cheapest.
- The sheet should first be cleaned with some dishwasher soap and a coarse sponge.
- Then, scrubbed under diluted hydrochloric acid.
- After the acid, it should be dried hopefully under an inert atmosphere and under that atmosphere it should also be painted.
- Now, over the painted and dried sheet, the hand sketching should be done as deep as possible and sketched lines should not be passed over more than one time (it is important that the surface under the sheet is hard and smooth, like marble; also, managing to sketch the figure on the back side of the sheet should cut your electrolyzing time in half!).
- For the etching part, the sketched part should be always submerged in a concentrated solution of sodium hydroxide (or just something strongly abrasive, depends on the paint you use) as hot as possible (wax may not be an option but you could try it without heating the solution) and electrolyzed with the highest (and safest) amperage you can get.
- The goal now is to get the "rust" off, as soon as it is formed; so constant movement of the sheet could be applied or maybe getting a constant stream of the same electrolyzing solution poured against the sheet could also work.
In the end I believe that it is more effective to go with the fast and powerful way (also more dangerous and maybe a little bit more expensive), than the time consuming and maybe more frustrating alternative.
I hope I was of some help, cheers!
Hey that's Bruce from rc model reviews! He's helped me a bunch with building racing drones
i have seen people using vinyl instead of paint, also i have seen that instead of soaking it in the liquid using a sponge soaked in electrolyte with the negative electrode inside it and the positive attached to the part to be etched can be used to etch, also the sacrificial metal (the negative) should be as similar as possible to the part being etched.
Alum, specifically hydrated potassium aluminum sulfate. I used it a lot to dissolve broken steel drill bits and burs from gold and silver. If I was going to attempt this its what I would try.
Using an alum chemical etching solution is on the to do list.
I have been doing a similar process with Kapton tape on the steel instead of paint, then using a diode laser to selectively burn off the kapton in the areas you want to erode. It seems to work fairly well.
Like others have mentioned, using something like salt or epsom salt would probably be less likely to mess up the paint, and I would try running a higher current/lower voltage to reduce bubbling. I use a cheap bench power supply and a big steel mesh as a cathode (higher surface area cathode closer to the etching part will give you higher current for a voltage).
1. I noticed the way you sprayed on the primer was very thick and lathered. Try doing 2 coats with the the sprayhead 8" away from the metal, let each layer cure fully to the specs on the can. Thinner and better adhesion is best. follow the directions on the can and treat it like paint for this scenario.
2. Your etches are VERY wide. This method counts on small particles being degraded and carried away. larger surface areas require more current however because of the way salt and baking soda react with the metals oxidation process, it is very difficult to control. So use very thin lines. This ties into the next 2:
3. Your Cathode is only a thin pipe used in plumbing. these pipes are metal alloys made to prevent errosion. This gives a VERY small area for the current to go through and will cause a lot of resistance (allowing the baking soda to just degrade the steel instead of carry it away). Use a plate/sheet of regular steel with a larger surface area than the play being submerged.
4. Use salt. It does not create rust as fast. Baking soda accelerates oxidation because of the reaction of Co2 and steel (were talking about oxygen versus chloride). use 1+ cup per 1.5 gallons of water. The more salt the better TO AN EXTENT ( you still want it controlled).
conclusion: for the best results, the cut material should be as thin as possible, the paint should be adhered properly (its not in your demonstration ;) ). The cathode should have a large surface area and not "resistive". The cuts should be THIN the more surface area on the "cut material" allows more oxidation and corrosion of the paint. No Baking soda is NOT a good alternative to salt. The oxidization from the water splitting in the cathodes should be enough to keep the chlorine from exiting the solution at a dangerous rate, if you are still concerned, vent it, volcanoes and manufacturing plants put out WAY more into the air than this project, you wont do any harm.
A little side note: this method isnt great for thick metal. when the area fisrt exposed to the solution is eaten away, it isnt 100% flat this means that the layer being eaten away next will be slightly larger than the first layer. Thinner materials like the spring steel used in the example video help with this as they are very thin. Here is a little diagram to show what I mean:
(^ is the entry point of the alkaline)
Thick material:
----------^--------------
*****/ \********
****/ \******
***/ \*****
-------------------------
thin material:
----------^--------------
*****/ \********
--------------------------
Etching or Chemical milling... done all the time...like printed circuit boards... ferric chloride is the etch for steel... I've used photo resist, also screen printed epoxy, or hand painted epoxy...there are tapes that are designed for etch of metal. With epoxy, curing temperature is important and a light/fine sanding of the surface prior to applying the epoxy paint. Also, know that as you etch down, a near equal amount is also etching under...approximately 45 degrees angle under the painted edge... so plan accordingly. On thick metal, and matching image is placed both sides and etched.
I don't have any ideas, but I love the vids!
michealcthulu does something similar to this on his channel when he has to etch things into steel. He, however uses vinegar instead of water, and uses a vinyl coating instead of the paint. It seems to etch more cleanly than this, and is faster too. I wonder though, if left alone, it could actually cut through. It would be a pretty cool thing to use, too.
Try using a rubber coating spray paint on top of the primer. I've used this system for precision electroplating and It always comes out great. The rubber gives me some really clean and sharp lines. I hope this helps!
I'm no chemist, but some technical differences I noticed in the inspirational video:
- The guy used a plate as a cathode as well, thus providing extra area
- He seemed to take care to ensure that both the anode and cathode are parallel
I don't know if any of the above-mentioned should make a difference but it might well play some role?
From the comments it seems that some people are in accord that salt instead of baking soda should be used. If you are cautious about the potential hazards of chlorine gas, you can try to isolate the anode and capture the gas and bubble it through some reagent to get it back into some solution. (I am not sure if such a reagent exists but it's an idea)
I hope you obtain success and I would like to see the end result.
If you think about it, increasing the pressure of the water could be the solution. When the etched metal erodes, the paint does not have enough stickiness to stick to the metal around the etched metal. So by applying force(water pressure) it could help the paint around the etched surface to stick to the metal as the etched surface erodes. Thus no water can seep under the paint.
Woow
This isnt even clickbait good job dude
ah love Bruce's videos.
if you haven't already, i'd suggest using the coating which was the most effective at not letting the electrolyte solution react with the metal and etching on the metal on both sides and deep so it has grooves which would mean the the reaction at the grooves would take less time to corrode through
Very interesting thank you! One thought, understands that it would be difficult to get it exactly. But if you scratched the color from both sides, it should be twice as fast plus that there will be no problem when it goes through the other side.
I used correction pen last time for pcb and it works. idk but it worths a try
You might want to try, if you haven't yet, rotating your anode and your cathode. When I was experimenting with producing Hydroxy gas with electrolysis, I noticed that one of my plates was getting beat up much faster than the other. Sadly I can't remember which plate it was.
Another thing you might want to try is replacing your electrolyte. KOH is much(!) less aggressive on the metal (and hopefully the paint) than table salt, and takes a far less active role in the reaction than baking soda.
Lastly, the problem might be the metal thickness. Once you etched through a portion of the metal thickness, the sides of that newly formed groove allow the process to move outwards from the cut, under the coat of paint. You might want to try repainting the metal sheet to cover those newly exposed parts.
Silicone protective coatings (anti corrosion in sea water) are great at adhesion to steel and resistance to demonstrated "bubbling"........ at least the ones I have seen in some lab tests (similar conditions to these in video), but that was some high end industrial stuff for dam gates.
Great tip! I bet a lot of marine paints would have potential.
I think you have to actually scratch in the etch then put in the tank. I saw a video of a guy doing that making a knife. I don't recall him coating it with anything. he just lightly scratched in his design then dipped it in some electrolyte acid. came out gorgeous.
I used to run into a similar problem with PCB etching. The key thing I discovered was to keep the etching time as short as possible. With PCB etching there are many well known tricks such as raising the temperature and agitating the etchant.
Toolmakers use a similar set of devices to cut intricate shapes. They are EDM sinker and wire. The first uses a graphite electrode to erode the metal, while the wire EDM is just that, a wire.
It's really simple, simple math and physics, all the exposed areas expose equally. If the line you scratch is wider than the thickness of your material, you don't have a chance. For thick material, the thinner your scratch line, the more control you will have over the etching, but it will always be a positive error the same thickness of the material.
It could be mitigated by multiple stages of painting and etching. Also using a very sharp and narrow awl to do the scratching, aiming for deep not wide lines. Also you could scratch from the backside as well, doubling the accuracy.
You could potentially calculate and accommodate this with the stencil. I think a hydrophobic coating might be worth experimenting with, due to the viscosity of water it may substantially increase etching accuracy.
I would suggest circulating the water, so fresh water constantly is exposed to the cut lines, and possibly a filter. Also, for the cut lines, perhaps applying thin vinyl strips where you want cuts, then applying the wax layer, then removing the vinyl, keeping the metal surface free of any wax vice the scraping the wax which may be leaving a residue.
1.use vinegar in as high of a concentration as possible as an electrolyte, as it creates more stable Fe ions in solution.
2. use thinner material, just like what AvE said.
3. You want high current , low voltage to erode fast, BUT high voltage, low current to erode cleanly, so you need to be able to find a sweet spot .
Here are some ideas I've had:
1) The gentleman who had this idea first had the metal in his tub perfectly vertical, maybe it could make a difference?
2)Try metals that are more/less conductive
3)Try metals that are more/less easily oxidized
4)Try different types of electrolytes, Try a bath of 100% Vinegar next please
5)Try using electric tape instead of paint (I love electric tape!)
6)The cathode was much bigger in the gentleman's video as well, might as well try that
7)Maybe you left the metal in for too long, the gentleman only gave it 20 hours for thin metal
I would use a neutral inert salt (like Na2SO4) so your product will be only H2 and rust or even an acidic enviromental (like dilute HCl) to prevent solid rust, the product will be a solution of Fe and everithing will be cleaner. For cathod almost everything should be ok but I would use something inert like inox steel or titanium. Cathod should be in front of the anode and should have a larger surface area. The thickness of the anode shouldn't be too big because corrosion doesn't go straight, so after a while you necessary erode even under the coating. For a cleaner coating you could try to mask areas that you would like to cut with tape, painting and then remove the tape.
I'm sure others here understand the chemistry far better than I, but it seems to me that you'll only be able to use this method on very thin sheets with any sort of accuracy. The corrosion eats away the metal in every direction, which at the beginning starting with a flat surface means that it eats into it roughly perpendicular to the face of the sheet. But as it starts to penetrate deeper it will start to corrode more and more under the paint till you get the bubbling up that your getting.Might be worth a try with something like shim stock.
I have done something similar but a bit differently. Instead of putting the metal in a fish tank I used a towel soaked in water and salt as a layer between the anode and cathode which were both steel plates. I used to use this method for just etching but I found if I recoated the area I was etching with wax and then just ran the end of a thin piece of wire through the groves I could keep the etching clean and make it deeper and even cut all the way through if I wanted to.
I forgot to mention I have had great success with using vinegar and salt instead of just plain water. Also just a fun idea that I found out on my own. If you put some steel in boiling vinegar it turns black and has a layer of carbon bonded to the outside. It is a cool easy way of staining knives black that I found totally on accident.
When I etched two metel pieces with a similar method I used waterproof masking tape.
That worked fine, the edges were pretty sharp, but I was only etching the surface, not through the whole piece.
Hey there Nighthawk, I haven't tried cutting with this method (though I might now), but a couple more ideas for the pile. Wrapping the piece in electrical tape and then cutting that out has worked for me in the past for etching. I also have seen other people using nail polish, which sounds promising, or even Sharpie marker.