Electrolytic de-rusting?

I have done this and it works really well well worth doing, I made a step by step on a woodworking forum I'm not sure you will be able to view it without signing up but give it a go:

www.ukworkshop.co.uk/forums/electrolytic-derusting-my-experience-wip-t17388.html?highlight=electrolysis

If you can't get washing soda (sodium carbonate) for Alan's recipe, which I couldn't source in Malaysia, I used baking soda (sodium bicarbonate) and it works extremely well.

DJ

I hear that the surface tends to be microporous and so tends to hold on to water and rust immediately (I expect it depends how bad the initial rust was).

I wonder if there is something you can dip it in that is miscible with water and so work your way around to white spirit or something else that will protect it. Or maybe there is a water based primer for iron - as water based paints seem to be appearing everywhere these days.

Have a look also at www.smex.net.au in the Reference section, and look at the article "Rust Removal"

Deeja

Good for cleaning pith helmets as well!

Strange how you guys just can't put a bone down - Cotswold got his answer and said thanks - now lets move along shall we?

As to clean pith helmets - they don't cut the custard like dirty ones.

DJ

OK Cotswold, then I'll have a nibble at the bone too.

I may be totally wrong, but my simple schooldays chemistry tells me the bubbles are oxygen and not hydrogen and appear at the positive electrode. The hydrogen being produced at the negative end (the bit being de-rusted) has a great affinity for the oxygen in the rusty metal and combines with it to do the derusting. The addition of the carbonate or whatever is just to make the water more conductive which speeds up the process. Basically it's just electrolysis of water.

Shoot me down with high faluting formulae! ;D

DJ

P.S. After all the rust has gone, add some copper sulphate and you'll get a nice fine copper plating on what was the rusty metal!! ;D

Of course, once you have a nice coating of copper, when you have dried it, you can then use that Goddards silver polish stuff and end up with a silver plated bit of what was rusty old iron!! The world is your oyster!

C'mon GS31 - in our day in Scotland, A levels hadn't been invented - it was highers and lowers, and Physics, Chemistry were classified as one - Science! OK, yes, biology was seperate but Maths was every aspect of the subject - In those days I got a mere 5 "highers" but probably now equivalent to 15 A-levels! But then we had to compete and not have the mamby-pamby society leveling the playing field to save upsetting the morons!

Oops - probably get this post deleted for being not politcally correct!!! ;D ;D ;D

DJ

My father was a research chemist and from a very tender age, he used to sit me on his knee in his lab at ICI in Grangemouth and show me stuff like the potassium iodate time reaction (for the uninitiated - en.wikipedia.org/wiki/Iodine_clock_reaction) and even the luminescene reaction to stimulate my interest in the subject. We always had a house full of carboys of the most dangerous chemicals imaginable, and I was a huge disappointment when I didn't follow in his footstesps and went off to be a quack instead -- but the teachings stuck.

Later, when I was more educated, I caught the old man one day sucking concentrated paraquat up in a pipette - I suggested to him that one drop on his tongue and he'd be dead - to which he replied - Ï've been pipetting far more dangerous stuff than this before you were born!

Hexavalent chromium is an orange colour I believe, clean the tank regularly and carefully. Any old rebar makes for an awful rusty mire you cannot see through to access progress.