Electro Etching Stainless vs carbon steel

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Randydb

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Sep 27, 2014
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Okay, I have been doing some reading/watching videos around making my own etching machine. My wife has a Cricut Cutter so I can make my own vinyl stencils.

At the moment I have access to very affordable AEB-L and a local guy about 20 minutes away who can HT it for pretty reasonable prices if I do batches of 8+.
So my reading...
The second post in this thread by Kdnolin shows a pretty simple and easy way to etch using a dc power supply and salt brine. I have 4 of those dc power supplies in my drawer. Kdnolin mentions using "positive ground to etch and negative ground to darken"

I also spotted this thread for making my own diy electro etcher.
Basically get ac and dc options. DC to etch and AC to darken.

But then I am reading about dc working better on carbon steel?

What do I need if I am using AEB-L. Will the chopped up power supply that Kdnolin shows in the cricut thread work for me on AEB-L? Or do I need to make the other supply in the youtube video to do stainless?

I would appreciate a simple "This is what to do with stainless and this is what to do with carbon steel."
Although I realize that very few things are simple in life.
 
The top etch is on 80crv2 and the fillet knife below is S35vn. I have not tried Aeb-l yet, but can’t see it being harder to etch than S35vn F714385D-189E-4679-90E0-48BC7484EFC1.jpeg
 
Be careful when electro etching, using the salt brine method produces chlorine gas at the anode and hydrogen gas at the cathode. The first is poisonous and the later is explosive flammable. Any method on stainless steel the byproduct is chromium in the solution. That is considered hazardous waste and illegal to just dump down a drain.

Ya often see how easy it is to do but rarely see the dangers associated with it.
 
neo71665 said:
Be careful when electro etching, using the salt brine method produces chlorine gas at the anode and hydrogen gas at the cathode. The first is poisonous and the later is explosive flammable. Any method on stainless steel the byproduct is chromium in the solution. That is considered hazardous waste and illegal to just dump down a drain.

Ya often see how easy it is to do but rarely see the dangers associated with it.
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Jesse Latham said:
Make the ac/DC etcher....Buy commercial etchant.
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Hmmmm....some good things to know. How much chlorine gas and hydrogen gas is produced? I remember a teacher making some hydrogen gas in grade 12 science and the beaker it was trapped in shattered when he sparked it. Does my respirator do it fine enough to handle the chlorine gas if I am in a well ventilated area?
What do people do to deal with these issues?

Does commercial etchant do a better job or not produce these gasses?
 
It really doesn't produce much just doing a little logo but the problem with chlorine gas is it doesn't take much.

https://en.wikipedia.org/wiki/Chlorine_gas_poisoning
Humans can smell chlorine gas at ranges from 0.1–0.3 ppm. According to a review from 2010: "At 1–3 ppm, there is mild mucous membrane irritation that can usually be tolerated for about an hour. At 5–15 ppm, there is moderate mucous membrane irritation. At 30 ppm and beyond, there is immediate chest pain, shortness of breath, and cough. At approximately 40–60 ppm, a toxic pneumonitis and/or acute pulmonary edema can develop. Concentrations of about 400 ppm and beyond are generally fatal over 30 minutes, and at 1,000 ppm and above, fatality ensues within only a few minutes."
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There is no antidote for chlorine poisoning; management is supportive after evacuating people from the site of exposure and flushing exposed tissues. For lung damage caused by inhalation, oxygen and bronchodilators may be administered.
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I'm not trying to be a safety sally but I've seen first hand what the stuff can do. Had an idiot pour salt on a battery spill at a work site trying to soak up the acid. He then stood in the gas cloud sweeping it up. He was disfigured pretty badly. Ended up having a hazmat team be called and the whole site shut down.
 
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Randydb said:
But...you are only using dc right? swapping leads to the steel to etch and darken?
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Yes, that’s how I did it. I don’t know how durable the darkening is yet, but I know some use gun blueing to darken, which should be permanent.
 
Just as Jesse said, if you wish to electro etch, then make (or get) an DC/AC power supply, get the commercial etchent and go from there. There is no real difference I've found between etching carbon steel and SS of several different types.

When you make stencils with the Circuit Cutter, doesn't it cut the material away so there is a full opening there? The normal stencil has a fine weave fiber that's coated. Where the logo is the coating is removed leaving the porous fiber that allows the etchant to soak thru and etch. There are several good sources of prepared stencils, or you can make your own nicely.

Good luck and have fun.
 
Ken H> said:
Just as Jesse said, if you wish to electro etch, then make (or get) an DC/AC power supply, get the commercial etchent and go from there. There is no real difference I've found between etching carbon steel and SS of several different types.

When you make stencils with the Circuit Cutter, doesn't it cut the material away so there is a full opening there? The normal stencil has a fine weave fiber that's coated. Where the logo is the coating is removed leaving the porous fiber that allows the etchant to soak thru and etch. There are several good sources of prepared stencils, or you can make your own nicely.

Good luck and have fun.
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I think the stencils you describe can be reused. I think from what I see of the ones being made with the cricut it's a one and done. But they do the same thing....protects the steel around the part you want to etch and lets the liquid get up against the parts you want it to affect.

I still want to know more about the chlorine gas and how people deal with that? Do people just do it with no protection or do they wear a respirator or what?
 
Yes, the stencils I described can be reused many times. Some folks are happy to get perhaps 20 etches from each stencil. I've got a buddy who gets 200 or more etches from each stencil.

neo71665 is talking about the salt water mixture and I've never used that, only commercial etchent. I suspect the amount of chlorine gas released each etch from salt water is so small it's not an issue. With that said, chlorine gas is nasty stuff and if you see a green cloud of chlorine, go the other way.
 
Ken H> said:
Yes, the stencils I described can be reused many times. Some folks are happy to get perhaps 20 etches from each stencil. I've got a buddy who gets 200 or more etches from each stencil.

neo71665 is talking about the salt water mixture and I've never used that, only commercial etchent. I suspect the amount of chlorine gas released each etch from salt water is so small it's not an issue. With that said, chlorine gas is nasty stuff and if you see a green cloud of chlorine, go the other way.
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Commercial etchant? I can tell you don't need much from watching videos...what product name do you use? Sold by?

Thanks.
 
I have been planning on trying ferrous sulfate as an etching solution (which **should** work based on the electrochemistry, and which others on the web have commented on as working well. Ferrous sulfate is a mineral supplement that you can buy at any drugstore. Take a bunch of tablets, break them up (or grind in a morter and pestle, and dissolve in small amount of **distilled** water. you ultimately want a solution where there are some small amounts of tablet pieces that are on the bottom of the container and do not dissolve (a "saturated" solution). Pour the liquid off of the pieces on the bottom and store in another container, and use from there.

You eat the stuff - so it is pretty safe. (I would avoid getting anything, no matter what it is, into the eyes though!)
 
Cushing H. said:
You eat the stuff - so it is pretty safe. (I would avoid getting anything, no matter what it is, into the eyes though!)
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Do you know what ferrous sulfate breaks down to when etching? You also eat salt, and the chlorine seems to be a concern to some. I don't know if ferrous sulfate can break down into anything harmful, or if the quantities generated could do any harm at all. But if safety is a concern, I would check the byproducts that might be generated.
 
Hubert S. said:
Do you know what ferrous sulfate breaks down to when etching? You also eat salt, and the chlorine seems to be a concern to some. I don't know if ferrous sulfate can break down into anything harmful, or if the quantities generated could do any harm at all. But if safety is a concern, I would check the byproducts that might be generated.
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Not absolutely clear, because depends on concentration and direction of current. But ... while etching you will either:
1) pull iron out of the metal and it goes into solution as iron iron inside of the wet electrode (this will happen in DC mode)
2) take iron from the wet electrode solution and deposit it onto the (part of what happens in AC mode)
3) the sulfate ion (SO4(2-) can get reduced to SO4(-) which is a medium strength acid. it will stay in solution in the liquid in the wet electrode pad, and not go anywhere (i.e. it will not be given off as a gas). Dont panic about the "acid" thing: remember that Coca Cola and Pepsi are quite acidic (PH of about 2.5) ... and you dont worry about that!. . The amount of SO4(-) produced for etching like this is so very small, you would be extremely hard pressed to measure any change in the pH of the electrode pad.

Bottom line - you are making stuff (iron metal, or SO4 acid that stays in the electrode pad, and does not go anywhere else). I can not prove it - but I will lay odds that at least some of the commercial electrolyte solutions (especially those for the more basic ferrous steels) contain at least some or a lot of ferrous sulfate.....
 
I use a 12 V variable AC/DC Lab use power supply @ 6V- I use AEB-L almost exclusively and use TUS stencils and SS Etchant.
I use both the AC and DC which gives a deep and dark mark- the black part of the etch is permanent. You need to sand it to remove.

Lots of examples of my etched logo on my IG:

https://www.instagram.com/p/B4IrdSGjeWY/
 
Could someone please show the steps when etching. When to use AC or DC, when or if changing polarity to darken, how long do you etch for, more like a step by step that would be great.

Thanks in advance,
Constantin
 
Do you have your stencils and etching machine yet? Really helps when you can practice. There are some really good videos around that demo etching very good. I looked and didn't find what I was looking for.

The first step is DC (positive to blade, neg to etching pad) that removes metal to form the logo. How long depends on the design, type of stencil, type of electrolyte, and voltage used. Typically in the 10 to 30 sec range should be good. Hold pad to stencil for 5 sec or so, lift to allow gases to escape, then press gently again, repeating until etch is at desired depth.

Next step is AC which will deposit the black to bottom of etch - normally total time will be in the 10 to 15 sec range.

IMPORTANT!!! Stencil must not move at all during the total time.
 
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