Author Topic: electrolytic cleaning with tig welder? (first results)  (Read 9238 times)

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Offline coppercone2Topic starter

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Re: electrolytic cleaning with tig welder? (first results)
« Reply #25 on: September 11, 2023, 03:30:55 am »
tried my theory about the phosphate/millscale which was really giving me trouble

I made this electrocleaning solution. beware it smells unpleasant compared to the phosphoric acid
https://www.eevblog.com/forum/rf-microwave/has-anyone-measured-performance-of-silver-plating-solutions/msg2999854/#msg2999854

the one with silicate.

Its not very 'bubbly' but for that piece of angle iron that has mill scale and or phosphate on it (real black, almost like paint), I first used AC (8.6 volts) on the carbon brush with the alkaline electrocleaning solution.

It did not have that much of an effect (it got the yellow rust off quick), but anyway after applying it with the electrobrush and brushing it for a bit (maybe a minute), I let it sit for like 5 minutes, then rinsed it.

Then I used the brush with the phosphoric acid solution. Its not fast, and the 'cleaned' iron looks dark, but it did strip it,

I really don't like the smell of the alkaline electrocleaning solution though, ugh. definately need ventilation.

So even low voltages for the AC work fine. If you have a big 9 or 12V transformer, its good enough, so long you can deliver the current into the ~0.5 ohm load. I like it because its basically zero splatter.

On aluminum, like an angle piece that looks 'cloudy', the low voltage AC cleaning does not really do much. You end up getting white patches, and honestly a stainless steel brush is much faster, But, after the brushing, if you go over it with the acid electrocleaner, it looks better. I feel like it probobly less contaminated, I think it looks just a tiny bit more shiny.


I am kind of thinking here that if you are using this thing, and you got a tray, so long you are safe, it makes sense to use the alkaline electrocleaning solution first on metal, to get rid of oil. I think the coating on the angle iron was having problems comming off because it was oily, and the lye should take care of the oil. I think it does. Not sure how much better it is to just scrubbing it with soap, but I imagine the TSP/NAOH mix is much stronger then regular soap, you don't need alot, and you can apply it with a brush and let it sit. I was hoping the electricity helps it 'get into' the stuff better. I imagine it does but its hard to tell, all the stuff I have is rather inconsistent.


I also tried it on perforation with the phosphoric acid solution. It gets rid of rust but the holes are still a problem. the sharp edges of a cut piece tend to cut the brush bristles. Prefer a evaporust dip here.

Does the two part solution of first cleaning with alkaline with a focus on degreasing and then using the acid for the deeper cleaning make sense? I think it might have merit but its a bit hard to tell. And I really don't like the alkaline cleaner odor. But I also don't like sanding god damn mill scale and rust, and I have a feeling this process can cut down on it greatly. You definately need a light clean before you weld though, but  this means just going over it with a brillo pad that is wet. A non super sharp one in the sink for a few seconds was enough to take away the residue to bare steel that is the right color. Similar to pulling it out of vinegar bath or whatever. Probobly gonna leave a few spots that are too tough and need to be scraped with sand paper, but it feels like less work.

So if you have a weird object you can't dip in evaporust made of mild steel that is rusty/milscaly, alkaline then acid low voltage AC electroclean carbon brush seems like a OK solution. A bit slower though, but much less messy.
« Last Edit: September 11, 2023, 03:39:10 am by coppercone2 »
 

Offline coppercone2Topic starter

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Re: electrolytic cleaning with tig welder? (first results)
« Reply #26 on: September 17, 2023, 05:34:34 am »
this information is basic but not that easy to find/notice IMO

The idea with the electro cleaning process is that O2 and H2 are produced on the surface (AC wave form), or only one gas with DC polarity.

apparently this has something to do with cleaning. O2 and H2 are not thought to be that reactive but maybe there is something going on the surface during the formation of the O2 and H2 (it does not come off the liquid as O2 and H2 immediately I don't think, its some kind of very small process. I think the belief is that its particularly disruptive towards grease.

With the polishing step people are thinking more about bulk metal migration, which is more intuitive. With the cleaning it seems that this comes to mind for the professionals.

Is some kind of very... active atom present O1 or H1 during electrolysis right on the surface before it merges with another one to make a diatomic molecule? If that interacts with say a strand of hydrocarbon gunk/polymer, does it behave in a aggressive reaction? Is there atomic hydrogen gas present there for a very short period of time whizzing around till it hits another hydrogen or something else? 

Kind of wonder if you are like forming margerine and oxidizing it ?'

I am imagining something like a strand of hydrocarbon that adhered to the metal surface. the electrolcleaning makes a H1 atom that enters the molecular chain of that. if you add or remove an atom I assume it makes it like contract and expand. Could this break it free? Not sure how long they are present for if they are present. Kind of like the process where you freeze something to make it contract and remove it (gum removal).

I  believe that is what a plasma cleaner does. Does electrolysis cleaning happen to do a similar thing?
« Last Edit: September 17, 2023, 05:53:40 am by coppercone2 »
 

Offline coppercone2Topic starter

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Re: electrolytic cleaning with tig welder? (first results)
« Reply #27 on: September 17, 2023, 07:11:42 am »
experimented on a larger dumpster angle iron (~2x2 inches and 1/4 thick and a bit over a foot long), with AC alkali clean then AC cougartron clean. (8.4V AC big ass transformer). I feel like this angle iron represents a realistic surface condition of a object we might be working with, if we have a semblance of being cost conscious. not your dolled up youtube starlett angle irons

Its not super effective. Got the red rust off pretty good but this steel had a real blue mill scale appearance on it.  It seemed that after a while the drippings were not changing color, and I got a big bluegrey puddle of electrolyte. Eventually the surface was not getting any cleaner,  The surface feels more level.

Afterwards I tried higher current DC, but throwing power at it did not seem to do much. It fumes more but the drippings did not seem as dirty as the prior attempt with AC.

 Post scrubbing with a brillo pad is not effective on this surface either.

here is the interior, which is uncleaned


the exterior after cleaning efforts



But what I think is MAYBE that this process first with less hazardous chemicals can be used before a HCl process to do a final clean. Getting a bit time consuming though... tommorow I will try to brush on some muratic acid to both sides to see quantities required for a cleaner clean, or if it even works to get rid of this coating. And see how much effort is required with a brush wheel. Kind of seems like its trouble some to try to use this but so is shitty mill scale dust being kicked up by a grinder

I was rinsing it with a spray bottle of baking soda water. The blue grey color of the steel appears to percipitate in the rinse drippings.

It should be noted that the high current DC (that did not seem to do much anyway) makes a substantial amount of fumes, but the lower voltage AC does not, it just gently bubbles.

I would say the ebay brushes don't like more then 25 amps unless your just dabbing them..


Would I feel better cleaning the post electrolytic cleaning piece? yes. I feel like I would be less concerned about clogging on disks, work time, etc. Would it save time?? not so sure about that one.

But I did notice with the last one that if you just leave the post electrolytic clean surface on it, even without oiling, so long you don't scrub, its kind of stable. This could theoretically allow for a pre-clean that can be left for a while with a easier final clean right before welding. Of course if you did it with  spinny brush, it would also be easier to reclean the oxide. but you would have to deal with the dust twice...  :-//
« Last Edit: September 17, 2023, 11:38:55 pm by coppercone2 »
 

Offline coppercone2Topic starter

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Re: electrolytic cleaning with tig welder? (first results)
« Reply #28 on: September 17, 2023, 08:50:53 pm »
I tried brushing on HCl with a silicone brush on the steel angle iron in a tray. It did not do much, and unfotunately the plastic bottle I had a bit of it in shattered on me, in the tray, but I just spend a good hour 1/2 re sanding the welding table. Don't trust plastic containers. It was fine last year but this year it got brittle (it used to be bendy polyethylene chemical storage bottle 500ml, not reused BS) I neutralized it and shit, but when I came back 3 hours later it had rust spots on that piece, from where the acid splattered. I used the phosphoric acid brush to clean up the rust, leaving it lookin better. then I wiped it down good with baking soda water, cleaned it with water, reground the surface with abrassive pads and then put a smear of grease on it. Hopefully that holds up OK. The abrasive pads clog up less if you clean the rust off with the electrocleaner.. so its suitable for spot cleaning (but it won't leave a nice surface, just not as bad).

But, anyway... I added like 2 parts of HCl to 5 parts of that phosphoric acid solution and stirred it up, and tried the electrobrush process (DC, 15V) on the angle iron. This time it was doing something. I feel like it got much cleaner. I sprayed it with baking soda water for 20 min and then washed it in the sink (was finishing regreasing the table)

It left some kinda... weird.. soapy?/buttery lookin white stuff on the steel, which rinsed off in the sink. Gentle scrubbing with brillo now brings on bare steel.

I think it might be possible to make this cleaning process usable for bad steel by doing a final pass with a HCl/phsophoric acid mix on the electrobrush. But the fumes of this one start stinkin like HCl. I think its more agressive cleaner with the electricity then just letting it sit on the surface. I think you can maybe clean some objects without a HCl dip tank using the phos/HCl mix on the ebrush. The reaction between the 32% HCl and the previously cleaned steel was not agressive when just dabbed on with  silicone brush, but it seemed to get agressive when the carbon fiber electrical brush was used.

i think there is different electrolyte mixes that can be made for different things like mill scale removal.  Keep in mind I used only used a small amount dissolved in a small amount of phosphoric acid in a small beaker (like 20 ml worth) to do this job, not a dip tank with a gallon of acid. it has some merit

now the angle iron has some kinda.. embedded stripes of mill scale right near the edge, maybe it was like 'skippin' in the extrusion machine to get bands like that, that won't come off easy. And after drying despite the neutralization it gets a bit of that post HCl - green/yellow steel 'patina'. Not sure how to get rid of that. I kinda wonder if you do a alkali electroclean (AC) after the DC HCl/Phos mix if it might get rid of that, instead of just a spray bottle rinse. probobly need to go back and forth a little bit.

i'd be pretty happy if I got a no-dip tank solution to cleaning dirty ass cheap/free steel up. Probobly always gonna need a final light pass on the wire wheel but i'd be happy with just dusting it. i'd say 90% better then starting.. might be useable if I work out the process a bit


btw if you add the HCl to the phos mix, you need to reduce the current. what happens if that phos acid stuff gets mad hot (hotter then BP of water) and I think its boiling off the HCl if you run it at high current. It boils off the HCl off the brush and leaves the phosphoric acid goo. Thats just making fumes without cleaning power, so turn it down on that step. I know this because if you dip the CF brush in the container after its been running hot,it sizzles, meaning its hotter then the boiling point of the electrolyte. if that acids doing anything its gotta be kept in the solution, because it really starts to stink like HCl on high current, but at low current its OKish.
« Last Edit: September 17, 2023, 09:09:40 pm by coppercone2 »
 

Offline coppercone2Topic starter

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Re: electrolytic cleaning with tig welder? (first results)
« Reply #29 on: September 17, 2023, 11:32:03 pm »
hmm I tried the alkali clean again, something to note

the mixture is foamy, the foam can explode. I had a few small pops and I turned the voltage down. Keep the brush moving don't let large amounts of explosive foam accumulate. Don't know why it was not happening before with AC. maybe the lower voltage, because i had it at 15V DC. Reduced it down to same voltage as AC and it stopped popping (8V). It was dragging arcs a bit, I assume maybe it does not arc enough with AC as opposed to DC to explode. Anyway with soap containing electrolytes be careful... AC might be safer then DC! I let it pop a few times before the larger foam exploded and made my ears ring so I adjusted the process parameters

Then I did the ~50:50 mix of HCl and phosphoric acid cleaner. It cleaned the mill scale off pretty nicely. The conductivity of this electrolyte is much higher, I was hitting the 30A current limit as low as 6 volts.

I then followed it up with another alkali DC clean after mostly neutralizing it with baking soda water. Some kinda stuff (its like dark grey cream) forms. Washes away easily.

Now the interior of the angle was maybe a bit cleaner then the exterior and it maybe got cleaned a bit in the previous testing, but I am impressed with this method. It was pretty fast, but it does fume, you need to manage fumes, its noxious. Since its not getting so hot you can dab the brush in the tray drippings to make the electrolyte last longer.

A bit smelly and requires equipment but I am impressed by the speed and low acid usage of this method.

The alkali post clean electroclean also got rid of the yellow greenish post HCl steel color, even as its drying.


So if you are wondering, does this process work with acids other then phosphoric? In a mixture it seems to definately improve the cleaning power, at the cost of fumes. I was happy working with the commercial phos acid mix, with the HCl not so much, needs more ventilation.

before


after. This was scrubbed with a coarse brillo pad for approx 15 seconds and dried with a towel after all the steps.


Very light bursh work needed, probobly a rotary tool with a wire wheel (standard right angle , not knotted) would take down the remains in a few seconds. The before I expect would be a hassle.

I kind of wonder now if I went over the last alkali clean with another phosphoric acid clean (without the HCl) to see how it would effect the post  cleaning corrosion when its drying after rinsing.
« Last Edit: September 17, 2023, 11:42:14 pm by coppercone2 »
 

Offline coppercone2Topic starter

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Re: electrolytic cleaning with tig welder? (first results)
« Reply #30 on: October 02, 2023, 03:01:15 am »
first real world use today. I used DC with the cougartron fluid to clean up a metal plate I had cut last year to act as a base for a atomic clock. It had spots of rust on it and a bit of pitting.

I cleaned it with the brush in a tray using about 10ml of fluid total on both sides (area about 6x4 inches).

It got rid of most of the corrosion, leaving the cold rolled steel plate looking a little grey. I washed it in the sink after wards and gave it a gentle scrubbing (approx 1 minute) with the brillo pad, and it cleaned up nicely. I then scrubbed it with an alcohol cloth, blow torch dried/activated it and spray painted it with primer/paint. I mean to scrub it off in the sink with the dremel power cleaning brush (single hand tool that spins a brillo) but it was out of batteries.

IMO the results were possibly exceeding using a wire wheel on it, but you can't get away from it, because deeper pits still need a bit of mechanical scrubbing to get rid of. But it becomes spot cleaning vs carpet bombing. There is not nearly as much surface damage as the brush.

I feel that using the wire wheel is a bit stressful in comparison.

I think its a valid method for paint prep. Maybe it took a little longer but no mess and IMO no danger. Before I started I attempted to clean a small section of it with a 2 inch rotary tool brillo brush (the milwakee variable speed polisher sander), and I noticed that its a very dirty process in comparison to the small amount of steam generated by the electrolytic cleaning brush. I also feel that the area is more suitable for painting then after using the wheel to clean it up. If you have seperate areas its less of an issue but it streamlined my process.

Feels like something you can do in the evening and not feel wound up lo, and its quiet.  I also feel less dirty then if I had used the wire wheel, meaning that I could take a detour from my normal routine to get this little job done. A rust removal soak would be better since its even cleaner and more thorough, but that is rather time consuming.
« Last Edit: October 02, 2023, 03:10:12 am by coppercone2 »
 


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