Howto: Cleaning parts using electrolysis

[Robby]

I'm fiddling with ways to sort out rusty metal without having to resort to a wire brush at the moment. Assorted things can work - coca cola is meant to be good - but a tried and tested method is electrolysis.

We all did this in GCSE chemistry, apart from the retards, so you have a rough idea of what's involved already - an anode, a cathode, and some electrolyte.

Most important things - this method is safe, easy, and requires no real work to shift the rust. If you manage to blow your garage roof off with a massive hydrogen pocket, I'll laugh and then come and piss on your dog.

This is for cleaning iron and steel components. I can't comment on aluminium, because I haven't tried it. Might work. Don't chuck your entire frame in just in case. If you are cleaning up aluminium or alloy, you should use a similar metal as the bit that gets worn away (positive/red clip bit).

You shouldn't use stainless steel as your erody bit, and I would prefer not to use it in there at all. Releases nasty chemicals apparently.

You will need:
A fair sized plastic container - storage box works well. Must be plastic, metal may get dissolved away or stop the reaction from working by completing the circuit.
A power source. You want around 12 volts and anything from 1 to 20 amps current. A car battery charger does the job, or a car battery hooked up to a charger. I have had the best results from an old PC power supply. The yellow wire gives +12V and 8-10A, earthing back to the black wire. If you can get a shock off it, its more power than you need. You need DC current - so don't hook it up to the mains.
Some scrap iron or steel. This will be the bit that gets eroded away. Iron reinforcing bar works well and is cheap. I used some steel tube offcuts. You will connect this to the positive (red) clip. Electrolysis works best in line of sight, so surrounding the container with old steel plate is effective.
Soda crystals, as used to wash clothes and things - as your mum. You'll need one or two handfuls to with about 50 litres of water. This is a normal size for a storage box. It isn't a precise thing, and its ok to use too much.
Chain or similar to dangle the part to be cleaned into the electrolyte. Wire isn't so good, and you don't want to put copper in there. Of course, if I didn't have chain lying around I would use wire.
Assorted clamps, jump leads, etc, to share out the current and stop stuff falling into the electrolyte.


What to do

1. Have a smoke. This is a quick process, you have time. Smoke two if you feel like it.
2. Fill your large plastic container with water. Set it down somewhere out of the way. Add soda crystals - a couple of handfuls.
3. Take your sacrificial iron or steel rods and arrange them around the edge of the container, clamped. Leave a couple of inches showing above the water line. Your aim here is to not let any of your clamps touch the water.
4. Take the part to be cleaned, and find a way of hanging it so that it is submerged in the electrolyte, and not touching the bottom or your sacrificial parts. Suspend using chain or something conductive. If you can't get it all underwater, this is ok. You can do one end at a time and this process will not leave a tidemark.
5. By now you have everything that is going to react sitting under water. Connect your sacrificial electrodes together (the more the better).
6. Take your power source. Connect the positive (red) lead to the sacrificial electrodes. Connect the negative (black) lead to the part to be cleaned. Do not fuck this bit up. Plug in the power source, if its a charger.
7. You should see lots of tiny bubbles in your solution within 15 seconds. The water will be pretty dirty within 20 mins. The whole process can take days, see my pics for why.


My experience with it:

1. Take a front suspension upright from a Ford Sierra. This has spent 15-20 years getting rusty and dirty. The brown shit is in fact a solid, 1-2mm thick coating of rust and dirt. Wire brush didn't scratch it.

https://www.bikechatforums.com/files/28102008442.jpg

2. Set up as explained above, after 5 minutes of reacting. Notice I am using a tub too small, so the part is not fully submerged. Also note two sacrificial electrodes, to make the shit coming off the part being cleaned go in two different directions.

https://www.bikechatforums.com/files/28102008444.jpg

3. Same set up, transferred to a deeper container and using. Also moved from using a big battery pack to a small charger, for ease of walking around it. This is after 3 days of reacting. The water will look like this after about 24 hours, and not look much worse subsequently.

https://www.bikechatforums.com/files/02112008447.jpg

4. The upright after 4 days in the soup. It has shed a coating of 1-2mm across its entire surface, the last bits of which I flaked off while drying it with kitchen towel. I can now see the factory stampings and markings again. The black coating can be rubbed off with a scotchbrite finishing pad prior to painting. to make the shit coming off the upright go in two different directions.

https://www.bikechatforums.com/files/02112008445.jpg

[calum17]

Amazing write up and a clever idea!

it's made me think about doing part of my bike's rear suspension linkage.

for the rod's can stell such as that found in big 'sheets' for reinforcing conrete floors and footings be good enough?

do you have to paint the part after it's been through this process or can it be left?


Thanks. really helpful!

[yandy_yay]

no i'm thinkin childrens paddling pool to get an entire frame in !

Good post, i will defo try this on some smaller items !

Thanks

Andy
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Current bikes: GN 125(now sold), Divvy 600s.

[SoND]

Nice one, came out great.

[rotax81]

cracking bit of info..... deffo worth karma
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[baldy]

I've done this before, it works a treat.

You are right about the gasses if you use stainless, but the up side is that it doesn't get eaten away.

You can also use caustic soda solution, along with those stainless steel tubs out of a deep fat fryer to put your stuff in.
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[Robby]

[calum17]

thanks for clearing that up for me - are there any specific laquers which should be sued over it - say if i did the linkage in my rear suspension?

[SoND]

[Robby]

I have no idea about specific finishes. For suspension components I'd paint them over with hammerite, trying to keep it out of the bits where the bearings go.

SoND - I don't own a bead blaster, but I think I have a paddling pool somewhere. Capital outlay would extend to buying 2 quids worth of soda. Then I can whip it out and hammerite it with a brush - tis a tubular spaceframe.

[cicatrez]

Just wow! Looks amazing.. Dude, thats a business for you right there! A good little money earner

[ZRX61]

Another method is get a couple of bags of molasses mix from your local feed store, mix it up & leave the parts in it for a few days.

[loply]

My inclination is that sandblasting would result in a better finish particularly as it leaves the surface ripe for painting (ie lots of grip), however, if I had loads of bits from a stripped bike to clean, this method sounds easier...

Sandblasting can be time consuming if you only have DIY kit (though it does work bloody well). Having said that, for one small bracket or something, it'd be quicker to blast it than to rig up all this stuff and wait 4 days.
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[MattHirst]

[The Shaggy D.A.]

This should be stickied
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[Kickstart]

Hi

Shot blasting heavily corroded stuff with a small garage compressor can take ages (and is a thoroughly unpleasant and dirty job).

[Robby]

Thanks for the stickiness Uncle Keith.

One eye bath later...

A few days on and some further findings:

The process is far, far more efficient with more electrodes.

Oddly, filthy water seems to be more effective than fresh - changed the water today, took a fair while to get back up to speed. Was a lot of crap sunk to the bottom though, nearly had a conductive floor.

Important one. The part will corrode within a few days, so get a finish on there quick. My personal favourite is hammerite, but a spray of undercoat or lacquer will do.


Going to experiment with washing the parts down in coca cola after the electrolysis bath next. Pics to follow in a few days.

[finpos]

I've done this as well, my 2p worth:

1. It seems to work best on surfaces that have "line of sight" to the sacrificial electrode, so use plenty of them.

2. Under the heading of "you wouldn't actually believe that works so well", you can actually separate things that have rusted together together (e.g. bushes in swinging arms) if you have enough patience.

3. If it's not working very well, you probably need a heftier power supply.

f.

[Mr Hammers]

Can't wait to try this at the weekend! Just gotta find some rusty things...

Just a thought... could the same process be used in reverse (switching pos/neg connections) to 'plate' metal...?

I'm thinking of either building up the metal again, or maybe even chroming parts...?
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[Robby]

I think plating is still done using an electric current, but with the item placed in a plating solution - not economically viable for home use. I know the chrome mix is very expensive and easily spoiled, which is why chromers won't touch exhausts generally, the carbon deposits in them will ruin the chrome mix.

If you run it in reverse you'll just very slowly dissolve the part you want to clean, and make it very dirty - after a few days your sacrificial part will look like it has spent 10 years underwater.

Best thing to do is put your rusty part in for a clean as described, leave it for a good while, then see how it looks. If there are significant defects you can try and build them back up with weld then grind flat, but if it works now that probably isn't worth it.

[Kickstart]

[Grav]

What a cracking thread. The idea had never even occurred to me before, cheers.
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snigger.....

[Paddy Blake]

Great tread Robby.
I just want to add two things.
I would take it apart first because you will most likely be changing the bearing.
If you have a compressor then when you take the part out blow all the water off it and oil any part that is a moving part.If you take it out and go for food it will be rusting before you get back.

Paddy.

[cagiva gezzer]

I use muriatic acid borrowed from work to clean parts.

Dump them in the acid (originally used to remove rust deposits from heating circuits) and pull it out a week later.

One has a 200L empty plastic drum if anyone wants . . . .
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[BanditsHigh]

Have seen the results of this technique first hand and it works a treat