# First attempt at hydrolysis rust removal



## Mel769 (15 Oct 2015)

Hi, today i set up a small hydrolysis tank to remove some rust from an old iron fire grate. So far it is definitely removing the rust as the water has lots of brown/green matter in it, the grate is bubbling away and looks good, im well pleased. However there is something i cannot get my head around concerning the sacrificial anode (s). I used 10 strips of hard steel, definitely not stainless, each about 1 cm wide and 3 mm thick. There is a definite build up of crud on the anodes' but it does not look like rust; its like a dark green flakey stuff with spots of white. The tanks been running for more than 24 hr's now, I take out the anodes' every 4-5 hours to scrape off this crud build up.

My question is this; I thought the anodes' were meant to collect rust, and/or disintegrate, so far they are not exactly heavily rusted and have not disintegrated. The hydrolysis is removing the rust from the item, but my sacrificial anodes' look surprisingly in good condition (after ive scraped off the crud), weird. Anyhow im now finding whatever I can to derust, its kind of addictive. 

Has anyone else found their anodes' are not disintegrating ? ?

Thanks


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## Monkey Mark (15 Oct 2015)

I tried this a couple of years back. It worked rather well. Perhaps it's the grade of steel you are using? My anodes basically disappeared after about 8 hours, though they were thinner than you are using. 

I think it was carbon that was the best to use as it doesn't deteriorate during use. 
If you have an old torch battery, the big square type with a spring on the top, you can get carbon rods from them.


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## Mel769 (15 Oct 2015)

Monkey Mark":34gcvuin said:


> I tried this a couple of years back. It worked rather well. Perhaps it's the grade of steel you are using? My anodes basically disappeared after about 8 hours, though they were thinner than you are using.
> 
> I think it was carbon that was the best to use as it doesn't deteriorate during use.
> If you have an old torch battery, the big square type with a spring on the top, you can get carbon rods from them.




Yes I have been searching for some carbon, think its graphite, but it is a bit pricey and would need a bigger surface area than found in them batteries i think but thanks for suggesting. Still no disintegration of my anodes' yet, I dont know, must be something in the water :duno: :duno:


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## Mike.S (15 Oct 2015)

When I tried electrolysis I found my anodes (just some angle iron) didn't visibly deteriorate but did get covered in crud - which I periodically cleaned off. I wonder if any copper (wire for the cathode maybe) is in the bath - perhaps contributing to the green tinge.


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## Higon (16 Oct 2015)

Mike.S":7beub1m5 said:


> When I tried electrolysis I found my anodes (just some angle iron) didn't visibly deteriorate but did get covered in crud - which I periodically cleaned off. I wonder if any copper (wire for the cathode maybe) is in the bath - perhaps contributing to the green tinge.




Depending on the mild steel / angle iron, it can have <0.5% copper, it might have been that you saw. 


A couple of things I'd suggest to anyone trying this is to ensure the anode is larger (in surface area) than the piece being cleaned! Do it outside! I've had a couple of 'cracks' from setups that started ok but after they had been running a couple of hours something sparked! A basket shape of 10mm wire mesh around the inside of your container gives better performance than a flat plate on one side. oh and never put washing up liquid in the mix.


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## ColeyS1 (16 Oct 2015)

I always add soda crystals to the mix, not sure why but think I read somewhere it alters the ph making it more effective :|
Coley


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## Mel769 (16 Oct 2015)

Well I broke the battery charger last night, must have shorted out so thats the end this experiment. The waste soup is not pleasant stuff to be fair, if i do it again I will try with some graphite electrodes but they do cost a bit.


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## Higon (16 Oct 2015)

Caustic soda works well too, IIrc, it makes the liquid more conductive.


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## AES (16 Oct 2015)

Mel, +1 for soda in the water (I used a hand full of ordinary washing soda and it worked fine).

I too got all sorts of crud on the anodes but I shouldn't worry about it, for me it worked fine if I just removed the anodes and washed them off once in a while. My crud was more black/brown than green BTW, but I guess that's more to do with the exact chemical composition of the parent metal and the anode/s. Didn't seem to affect my de-rusting process when cleaned off.

Aldli and Lidl have cheapo car battery chargers from time to time - worked fine for my de-rusting when set at about 1 amp.

But if you think you've blown your charger I suggest you check the fuse first (in the charger, not the one in the mains plug).

HTH
AES.


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## Racers (16 Oct 2015)

The electronic chargers from Aldi/Lidl won't work they don't like being connected to anything other than a battery.
Find an old cheap one from a carboot etc.
Or knock one up from a transformer and rectifier.

Pete


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## AES (16 Oct 2015)

Don't really know if my cheapo Aldi charger is electronic or not, but as said, mine worked fine for de-rusting. I did buy it a few years ago.

AES


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## Phil Hansen (17 Oct 2015)

I converted an old computer power supply (lots of links on the web). Works fine.
Also got some carbon gouging rods from a welding supplier. 
They had a thin copper film which peeled off easily.
They do not coat up but do make the solution black.
Phil


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## thick_mike (17 Oct 2015)

Old power supplies for various redundant equipment (Wall wart type) work well too. I used old phone chargers with the connectors stripped off. If you need more amps, try an old laptop charger. Make sure you strip the wires at the DC side though and not on the mains side!!!


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## seaco (19 Oct 2015)

I have used this method several times as long as you can supply 12-18v DC you can use most things I've used a car battery charger a Hornby train transformer and now an 18v transformer all worked I add some washing soda to the water and I use two anodes 200mm x 50mm x 6mm and I have stripped a machine vice weighing 80lb+ in 24hrs see this link:

another-successful-electrolytic-derusting-project-t80550.html

Hope it helps...


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## Mike.S (19 Oct 2015)

Higon":255dw8ie said:


> Mike.S":255dw8ie said:
> 
> 
> > When I tried electrolysis I found my anodes (just some angle iron) didn't visibly deteriorate but did get covered in crud - which I periodically cleaned off. I wonder if any copper (wire for the cathode maybe) is in the bath - perhaps contributing to the green tinge.
> ...



Possible, thank you Max.



Higon":255dw8ie said:


> . oh and never put washing up liquid in the mix.



Hhmm. I haven't but I'm curious why you shouldn't? To a layman like me it might act as a surfactant to improve the 'olysis'.


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## woodpig (19 Oct 2015)

I used washing soda which worked fine and with no noticeable reduction in the anode. I wouldn't use caustic soda though as it may cause pitting on the item to be cleaned.


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## thick_mike (19 Oct 2015)

Washing up liquid will trap any hydrogen and oxygen produced...any source of ignition will make a bit of a crack!


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## Mel769 (21 Oct 2015)

Just to update, I have now bought another charger having overloaded my ancient 1940's museum piece (bit gutted about that); I went for an Absaar 8a (6&12v) from Amazon at only £20 and its a solid well built charger that electrolys's well. A word of caution thou regarding the soup, if you try to siphon it into a bucket avoid getting a spitfull in the mouth, I inadvertently swallowed some and half hour later my stomach was rumbling like never before and i was on/off the crapper with the squits for about 5 hours. Not good, although I feet fine the next day; hope ive not any lasting damage to my innards.


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## chaoticbob (21 Oct 2015)

Mel769":321y9pei said:


> A word of caution thou regarding the soup, if you try to siphon it into a bucket avoid getting a spitfull in the mouth, I inadvertently swallowed some and half hour later my stomach was rumbling like never before and i was on/off the crapper with the squits for about 5 hours. Not good, although I feet fine the next day; hope ive not any lasting damage to my innards.



Good God man! What electrolyte were you using? Not caustic soda I hope!

Robin
.


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## Mel769 (21 Oct 2015)

chaoticbob":3a8j0uxj said:


> Mel769":3a8j0uxj said:
> 
> 
> > A word of caution thou regarding the soup, if you try to siphon it into a bucket avoid getting a spitfull in the mouth, I inadvertently swallowed some and half hour later my stomach was rumbling like never before and i was on/off the crapper with the squits for about 5 hours. Not good, although I feet fine the next day; hope ive not any lasting damage to my innards.
> ...



No not caustic soda, I used "soda crystals",


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## AES (21 Oct 2015)

Crikey Mel! From just looking at the "gunge" left over from my own de-rusting I wouldn't ever consider siphoning it! I just pour it into a big bucket through an old nylon mesh filter with lots of water from the hose and put the remaining sludge into old tissues and newspapers for throw away.

Hope you're really OK now.

AES


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## Mel769 (21 Oct 2015)

I feel fine now thanks; it really does go right through you thou, rapidly.


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## johnbaz (26 Oct 2015)

I had a go at cleaning some old coins in a little setup, As an anode I used a piece 15mm copper water pipe that I cut out and flattened, I used a low amperage car battery charger, It did the job Ok-ish

The coins had, I believe been underwater for a couple of hundred years so were badley eroded!!

I don't know why but some of the coins turned the electrolye yellow, Othe made it go brown!!







Brown!






Yellow!!






The coins before..






And after!







There was still some verdegris on some of them!!

By the way, I also tried some aluminium as an anode but it melted!! :shock: 



John


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## Mel769 (26 Oct 2015)

Apparently you should avoid using copper as a sacrificial electrode as it turns the piece to be cleaned copperish (as you have found). If you use steel it tends to cover the piece being cleaned with black magnetite and this should be removed fairly quickly. Ive discovered a good lotion to remove this magnetite can be made by mixing baking soda - toothpaste - and water, then give it a scrub with a green kitchen pad. It does a fairly good job of removing the black stuff. I have just completed a clean up of an old iron fire grate and is looking good, I will post some photo's tomorrow. 8)


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## Mel769 (27 Oct 2015)

Here are some before and after pics of my fire grate for anyone who is interested; after an electric bath and a bit of blacking polish its looking alot healthier.


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## blackrodd (27 Oct 2015)

I this system better than white vinegar?
Regards Rodders


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## dickm (28 Oct 2015)

Mel769":1186eju0 said:


> Here are some before and after pics of my fire grate for anyone who is interested; after an electric bath and a bit of blacking polish its looking alot healthier.


Blimey, that must have been some bath!!! Or did you just adapt your swimming pool??


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## MCB (31 Oct 2015)

I've used RESTORE products from Shield Technology with a great deal of success

It doesn't require electricity - just leave in solution (longer the more rusty it is )

It's freed screws that were rusted solid for me


MC Black


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## chaoticbob (31 Oct 2015)

blackrodd":1o9zalik said:


> I this system better than white vinegar?
> Regards Rodders



Vinegar, being an acid (albeit a weak one) will attack the underlying iron to some extent. That may or may not be a problem. Electrolytic reduction 'deals' with the rust by converting it to other iron compounds - exactly what depends on pH, voltage, current density and the phase of the moon I dare say. Electrochemistry tends to be messy as shown by the pics of 'soups' in this thread - but the main advantage of the electrolytic derusting method AFAIK is that there is zero chance of attacking the base metal further than the rust has already done. 

Mel, glad the intestinal effects were transient! Actually, thinking about it, all you had in there was sodium and carbonate ions from the soda crystals and iron - not a deadly combination taken in moderation. 

I'll get me (lab) coat.

Robin


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## Mel769 (1 Nov 2015)

blackrodd":165gmwy5 said:


> I this system better than white vinegar?
> Regards Rodders




I have found that using white vinegar does a great job, however there are so many variables including the type of metal being treated, space/time ect ect. I have found that while vineger works well it can turn _certain_ metals a dull greyish colour For comparison, you can see below two lawnmower blades that were heavily rusted. The one below was treated with vinegar for about 3 days, the top one with electrolysis for 1 day.


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## woodpig (1 Nov 2015)

You can also use citric acid but that eats into the surface as well leaving a dull surface.

If you have a battery charger washing soda is very cheap in the supermarkets and safe to tip down the drain afterwards.


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