De-rusting by electrolysis- Part 1

jack of all

Ok, as promised: "De-rusting by electrolysis- Part 1"! I made reference to this in another thread, only getting around to it now. There's loads of good information available on der interweb but my basic set up is this:

1. A car battery charger with ammeter (I'm using a Ring 20 amp charger, more than enough juice for my small bucket).

2. 12 volt battery wired in parallel (to reduce current drawn- in fact my charger won't allow current to flow without this,I presume this is due to some inbuilt electronic safety feature as the electrolyte has a low resisistance on its own?

3. Plastic bucket, drilled around the top circumference to receive anode tie wires.

4. Sacrificial anodes, some 12mm rebar, cut to length and tied to bucket, through holes.

5. Connect the lot up with crocodile clips- positive to anodes, negative to item for de-rusting, avoid shorting.

6. Some experimentation is required to ensure that excessive current is not drawn- I'm aiming at between 2- 5 amps. Hydrogen gas is produced so no naked flames in the kitchen please! (I've got a nearby window open for good ventilation)

Switch on and wait....I removed it after a few hours last night to have a peek- pretty good with lots of rust and crud having been removed.

I'm only halfway through the process on this old rusty weight, but I'll post pictures on the completed article... As for electricity cost, I'm guessing at 5 amp/ 12 volt with a conservative transformer/ rectifier efficiency of 75% that this set up will cost somewhere in the region of 50 cent per day to run.

Double Barrel

Plus one Jack of All

aerosol

Very good Jack of all. Fair play to your missus for allowing you to play in the kitchen:D

jack of all

aerosol wrote: »

Very good Jack of all. Fair play to your missus for allowing you to play in the kitchen:D

Ha ha lads, she's used to it! The missus wasn't too happy this evening when I set it up again for another few hours! It has to go back into the back hall before I hit the hay tonight.

Anyway I took the weight out for a mid-way look, see the pic; another few hours to go. So far the operation has removed a few tablespoons of scale and crud (the weight won't pass the scrutiny of the Legal Metrology Service now!).

jack of all

Ok, here's the finished article:

I think it cleaned up pretty well; I did give it a very light going over with a wire brush mid way through the process to hurry things along. A final scrub with a nylon scourer revealed a sound surface, perfect for painting. I look forward to trying this out on some old tools and bargain finds!

ennisa

Excellent result, how much do you reckon this cost to set up from scratch Jack?

I was surprised how well the citric acid bath worked but that was on items with a lot less rust etc.. maybe if you wanted to do a two step process you could do that first.

What would be the safety concerns about using citric acid in the water that you are using for the electrolysis? Would it enhance or impede the rust removal?
Citric acid is what is used in coke and I was able to use my hands without gloves in the concentration that was needed to derust some plane irons and chip breakers. I'm not sure how man moles of citric acid that is, I'm struggling desperately to remember leaving cert chemistry

jack of all

Thanks Ennisa; initial set up cost came to around €80, mostly because I decided to buy a decent charger (this was nearly €70 on ebay). You could use a cheaper no name brand charger but an ammeter is very useful to gauge progress and identify problems with electrical conductivity. The advantage of this over other methods (citric and phosphoric acide for example) is that this method apparently converts some of the solid rust back into another form of iron. The chemistry on this is complex but there's plenty of reference material on the web. I know that this set will save lots of manual work in the future, especially when I think back to hours spent trying to salvage old tools, car parts etc- wire brushing and steel wool only get you so far! I reckon this will pay for itself in time.

dubtom

Just got back from France with a WW1 18 pounder shell and a basket case of a Royal enfield rifle. The center part of the shell has a big build up of rust and probably dirt,but it also has two brass bands on it,would electrolysis work on it I wonder,without damaging the brass? The rifle is bent and rust has worked through the metal completly in some places but I'd still like to clean it up. I may trouble you for some simpler terms of instruction jack of all, wires and electricty aren't a strong point for me,never mind including water in to the mix.

Double Barrel

Fair play to your missus for allowing you to play in the kitchen

:D

http://www.htpaa.org.au/article-electro.php

jack of all

Hi Dubtom, Double Barrel's link above gives you all the info you need and there's plenty more online. I would just add the following few things to be aware of-

1. Only use washing soda for the electrolyte.
2. Switch off the charger when inspecting the items, hydrogen gas is produced so avoid short circuiting due to explosion risk!
3. Don't use stainless steel for the anode.
4. Turn the pieces regularly to ensure that all parts of the item are being treated. Remove the item halfway during the process to remove the black sludge. This allows you to monitor progress and helps to improve efficiency.

Have fun!

aerosol

Jack,you've inspired me to have a go at this:D

Just scored this little fella from dublinwaste,its in bad need of some tlc.Anyone have a guess at its intended use?The jaws spin through 360o.

Fingalian

Interesting looking vice. Metalworkers of some type, judging by the anvil? Maybe a jeweller/silversmith? Nice find:)

jack of all

Nice find, should clean up well; as for it's use? No idea, is it designed for clamping discs with hole (I'm guessing here!)?

Alun

What a strange looking device! It initially looks like it would be used to hold something circular with a hole in the middle (a wheel of some sort?), but then not only does it look as if the central shaft doesn't come out fully, the inner set of jaws doesn't extend out past the base, so any kind of circular object would foul the base. There are some interesting grooves (cross shaped) in the left inner jaw, that aren't on the right inner jaw too. Very odd.

ennisa

it has a kind of boaty, marine look about it. Never seen anything like that before though.

jack of all

Curiosity got the better of me, looks similar to one of these:
http://www.yostvises.com/rotating_vise.htm

"A multi jaw, rotating pipe and bench vise". Now, do I win a prize?:D

Alun

jack of all wrote: »

Curiosity got the better of me, looks similar to one of these:
http://www.yostvises.com/rotating_vise.htm

"A multi jaw, rotating pipe and bench vise". Now, do I win a prize?:D

Well done! I must admit to having a bit of a Google myself, but didn't find anything.

aerosol

Excellent thanks,and the prize goes to................ME for scoring it!!!!:D:D

Just have to clean it now,also it doesn't have anyway(other than 3 small holes at the back which aren't really suitable) of securely fastening it to a bench. Think it must use the holes either side somehow....

Just on vices;)(I've sooo many!!!!)A friend gave me this big fella,I need a serious bench just to put it on.

Just need to find a woodworking one now:)

dubtom

I got one of them from a mate,it was lying in his back garden for years,unfortunatly it seized up on me after a little use.The quick release doesn't work for some reason,wonder if that would be a good candidate for electrolysis.

jack of all

dubtom wrote: »

I got one of them from a mate,it was lying in his back garden for years,unfortunatly it seized up on me after a little use.The quick release doesn't work for some reason,wonder if that would be a good candidate for electrolysis.

I reckon so, electolysis will get to the parts that other methods can't reach, as long as a good electrical connection can be made.

madrab

Did you use anything to treat the surface from rust after electrolysis?