taiwanluthiers Posted January 9, 2016 Share Posted January 9, 2016 I know this is a bit off topic... But here goes: Some people are using the (per)chlorate process to etch metal. Basically make a mask, then place a solution of salt on the surface to be etched. Then pass a current through it. The process will obviously erode the metal but the mask prevents the unmasked portion to be eroded, thus marking the metal. Anyone have any detail on this? Link to comment Share on other sites More sharing options...
Mumbles Posted January 10, 2016 Share Posted January 10, 2016 I moved this to it's own thread. Link to comment Share on other sites More sharing options...
mikeee Posted January 15, 2016 Share Posted January 15, 2016 You could check YouTube there are quite a few video's posted on related topics like this one. Link to comment Share on other sites More sharing options...
Col Posted January 15, 2016 Share Posted January 15, 2016 This is a good one Link to comment Share on other sites More sharing options...
Mumbles Posted January 15, 2016 Share Posted January 15, 2016 I've been looking into this as well. I've gotten back into homebrewing, and was looking to etch my boiling kettle. https://byo.com/stories/issue/item/3113-etch-your-kettle-projects Was there anything in mind you had to etch? The process looks pretty simple for just surface markings like this. There is a somewhat more in depth process to do relief etching where you take off a noticeable amount of metal. It's essentially the reverse process of electroplating. Link to comment Share on other sites More sharing options...
taiwanluthiers Posted January 16, 2016 Author Share Posted January 16, 2016 Yea, all I really wanted to do is etch markings into metal item, without having to use a CNC mill to engrave it in. I got a laser engraver (a really cheap one) and I'm thinking to stick vinyl onto the metal, use the laser to cut the stencil out, and then use the electro etching process to mark it. It only needs to be deep enough to show. I tried it with just salt water and the etching seems to be extremely shallow... I'm hoping to etch it at least .005" deep. Link to comment Share on other sites More sharing options...
MrB Posted January 16, 2016 Share Posted January 16, 2016 Yea, all I really wanted to do is etch markings into metal item, without having to use a CNC mill to engrave it in. I got a laser engraver (a really cheap one) and I'm thinking to stick vinyl onto the metal, use the laser to cut the stencil out, and then use the electro etching process to mark it. It only needs to be deep enough to show. I tried it with just salt water and the etching seems to be extremely shallow... I'm hoping to etch it at least .005" deep. Depth has a direct relation to time in this regard. I'm not convinced vinyl is your best option tho. I'd use a paint. Preferably a etching paint, but if need be, automotive paints can be tested. (and are dirt cheap) Automotive paint is harder to remove...B! Link to comment Share on other sites More sharing options...
MadMat Posted March 24, 2016 Share Posted March 24, 2016 (edited) You can electroetch metal with a large variety of chemical solutions. Additionally, you can get a variety of resulting finishes depending on the solution used. There was a book that was akin to a metal finishing bible that contained all sorts of information on plating solutions, conversion coatings, electro-machining solutions, ect. Unfortunately, it's been a LONG time since I worked in the laboratory at metal finishing companies and I can't remember for the life of me what the name of that book was. I believe you could start out experimenting with a variety of hydroxide salt solutions or. a salt of the metal you are trying to etch (IE. ferrous sulfate for iron, copper sulfate for copper ect.). There is a "paint" used for masking the traces on printed circuit boards during the chemical etch process that should work quite well. Electronics supply places would be a good place to start to find it. There is also a masking paint used in the plating industry that would work very well, but my guess is that it would be rather pricy. This paint remains rather rubbery and is removed by manually peeling it off. As far as getting a desired depth of etch, don't try to rush it. Keep the current on the low side and be patient. Edited March 24, 2016 by MadMat Link to comment Share on other sites More sharing options...
taiwanluthiers Posted March 25, 2016 Author Share Posted March 25, 2016 I have used my laser to etch a piece of vinyl as a mask, and it works really well as long as you can prevent the solution from touching the metal in other places. At first I used the "engrave" setting to burn away the vinyl but in addition to creating caustic smoke (that could harm the laser assembly) it really did not burn away enough vinyl to make an effective mask (the aluminum seems to make a very good heat sink material, meaning the aluminum will cool the layer touching it enough that the laser won't burn it). Instead I just left the vinyl on its original sheet and adjusted the laser power so that it cuts through the vinyl but not the backer... it worked out better than I expected. For solution, I used a solution of vinegar and salt... and just pooled the solution onto the part I want to etch and pass electricity through it. It only took a few minutes to etch about .005" deep... it's surprising how much metal it can remove! I wonder if this process could be used to machine metal... instead of using blades to machine the metal use the electricity to remove them one molecule at a time... if only it were possible to do this precisely. Link to comment Share on other sites More sharing options...
MadMat Posted April 3, 2016 Share Posted April 3, 2016 You can definitely electro-machine metal, but it has serious limitations. The worst one being that sharp edges or simply the ends of a part would be "eaten" away faster than flat surfaces in the middle of the part. The reverse happens in electroplating, and many times pieces of sheet metal are added onto the end of a part (called "robbers" in plating lingo) to try and make the plating more even. Link to comment Share on other sites More sharing options...
dagabu Posted April 4, 2016 Share Posted April 4, 2016 (edited) I know this is a bit off topic... But here goes: Some people are using the (per)chlorate process to etch metal. Basically make a mask, then place a solution of salt on the surface to be etched. Then pass a current through it. The process will obviously erode the metal but the mask prevents the unmasked portion to be eroded, thus marking the metal. Anyone have any detail on this? I use this method on my stainless steel and aluminum kettles for home brewing. I use a 12V power supply and a 1 TSP salt per 2 oz vinegar and lay the pot down before etching. I also let it bun in deeper. There are MANY videos on YouTube for you to find a method you like. https://youtu.be/pUkgDtYMsgg?t=266 Edited April 4, 2016 by dagabu Link to comment Share on other sites More sharing options...
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