First attempt at hydrolysis rust removal

[Mel769]

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

 

[Monkey Mark]

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.

 

[Mel769]

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:

 

[Mike.S]

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.

 

[Higon]

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.

 

[ColeyS1]

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

 

[Mel769]

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.

 

[Higon]

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

 

[AES]

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.

 

[Racers]

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

 

[AES]

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

 

[Phil Hansen]

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

 

[thick_mike]

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!!!

 

[seaco]

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...

 

[Mike.S]

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.

Possible, thank you Max.

. 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'.

 

[woodpig]

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.

 

[thick_mike]

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

 

[Mel769]

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.

 

[chaoticbob]

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
.

 

[Mel769]

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
.

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