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Peter-C
21st December 2009, 10:08 PM
What parts have been derusted using electrolysis, I fancy having a go tomorrow.

Peter

alga
21st December 2009, 11:34 PM
Anyone strong in chemistry? What reactions are going on on the electrodes?

In my limited understanding, on the cathode Na+ gets an electron, turns into metallic Na, which then reduces Fe2O3 to Fe and Na2O. This in turn reacts with water, turns into NaOH + H2. Bubbles.

On the anode, CO3-2 gets looses the charge, turns into CO2 and O2, bubbles. Right?

I think the solution must turn progressively more alkaline as CO2 escapes.

davidimurray
21st December 2009, 11:41 PM
Powler - you can chuck just about anyhting metal you like in, but I wouldn't reccomend anything with bearings in. I've done drums, brake backplates, calipers, engine pulleys etc etc

Alga - I thought I read somewhere that the reaction gave off Hydrogen

gingea1pom
21st December 2009, 11:46 PM
This month’s CKC has a good article on the whole electrolysis/chemical de-rusting thing.

Also a picture of a rather striking bloke on page 56 (picture 38, the one on the right)

alga
22nd December 2009, 12:04 AM
Awww, going to check the mailbox...

Nope, still empty. And it's frigging -15°C outside!

gingea1pom
22nd December 2009, 12:14 AM
I would wait for it to turn up; it is a 5 page article with 32 pictures.:D Very good

alga
22nd December 2009, 03:07 AM
OK, the exact chemistry is a mystery even to specialists, here's an article about it: http://www.holzwerken.de/museum/links/electrolysis_explanation.phtml

Land Locked
22nd December 2009, 06:57 AM
There was an article some time back explaining why one should not use stainless. link (http://www.locostbuilders.co.uk/viewthread.php?tid=9158&page=8) (about 4 posts down)

adrianreeve
22nd December 2009, 07:41 AM
I did my sierra front and rear hubs, and have just done all four calipers - it's brilliant and will send you looking for more rusty stuff to do!

If you can, I would use a sheet of mld steel rather than strip, as you will get quicker results.

The great thing is the process won't attack good metal, so bearing surfaces etc are unaffected

Cheers

Adrian

Peter-C
22nd December 2009, 10:37 AM
Cheers,

Hubs here we come !!

Peter

alga
22nd December 2009, 11:58 AM
The great thing is the process won't attack good metal, so bearing surfaces etc are unaffected


Yep, it does not etch rust and metal, it reduces rust to metal.

Tatey
22nd December 2009, 12:21 PM
Has anyone got a list of things you need for electrolysis? I'm trying to find a list and a guide but i can't seem to find one.

Also does it damage rubber seals etc? Finally what parts am i allowed to do? I know not to do disc brakes or the flywheel as they could suffer from hydrogenation (i think) and become brittle and shatter :eek:. My plan was to do the brake callipers, brake drums, front uprights and some other stuff if it works well.

dan_g8
22nd December 2009, 01:06 PM
all you need is an 12 volt car battery charger, baking powder, a container to put your parts in and some scrap steel to surround your rusty part.

connect the + side of the charger to the metal surrounding your object and the - side to the object. pour the solution of water & baking powder into the container with your object and leave over night.

DO NOT USE STAINLESS STEEL THOUGH!!!!! it turns your water very toxic & harmfull. also dont get you + & - mixed up or your rusty part will be eaten away!

dan

Tatey
22nd December 2009, 01:08 PM
What else can i use other than a 12v car battery charger? As i don't own one at the moment.

Cheers for the guide tho.

Bonzo
22nd December 2009, 01:11 PM
Here is an interesting artical in PDF format

Elecrolytic rust removal (http://www.fergusonenthusiasts.com/restoration%20helps/tech/Rust%20Removal%20Using%20a%20Battery%20Charger.pdf )

This should help explain the basics & give a general idea of what is needed :)

dan_g8
22nd December 2009, 01:19 PM
you can use anything that puts out arround 12 volts, 2amps & is DC.

Dab

tigmatt
22nd December 2009, 05:32 PM
Here is another good link on electrolysis
http://www.stovebolt.com/techtips/rust/electrolytic_derusting.htm

Tatey
22nd December 2009, 06:06 PM
Where does everyone buy their washing soda from? I had a look in Tesco earlier and i couldn't find any.

Cheers for the help so far :D.

adrianreeve
22nd December 2009, 07:39 PM
Soda crystals in the cleaning aisle of any supermarket.

Cheers

Adrian

frankie boy
22nd December 2009, 08:30 PM
Soda crystals in the cleaning aisle of any supermarket.

Cheers

Adrian

What is a supermarket and where do i find one.:D

adrianreeve
22nd December 2009, 08:36 PM
I'll let you know in exchange for a bodywork set when they're ready!

Cheers

Adrian

walter
22nd December 2009, 09:40 PM
Hi all one thought on drusting parts ,if you know any one with a saftykleen degreaser,they do a liquid derusting soloutin which we tested for them at work,i thought it was going to be a gimmick, but it was brilliant and did what it said on the tin all you do is drop the part into the solution and leave it do its stuff .

les g
23rd December 2009, 12:46 AM
Hi all one thought on drusting parts ,if you know any one with a saftykleen degreaser,they do a liquid derusting soloutin which we tested for them at work,i thought it was going to be a gimmick, but it was brilliant and did what it said on the tin all you do is drop the part into the solution and leave it do its stuff .

yep thats right we done the same at our work
its bloody expensive through them though
but the solution is talked about in the magazine article and available on the open market now walter
cheers les g

les g
23rd December 2009, 12:49 AM
What is a supermarket and where do i find one.:D

frankie boy
its like a pub or an offy you can buy beer and spirits there
but you cant drink em on the premises
i think they do stuff for barbecues as well
cheers les g

happyjo
30th December 2009, 01:27 PM
Guys I found this website from the USA.

http://users.eastlink.ca/~pspencer/nsaeta/electrolysis.html

Very good, explains why it works, what you need and what not to use.
Even suggests using a battery with the charger which helps the process and stops the parts/ charger causing problems for the charger and part being cleaned.:)

When I have my donor car then the soda crystals will be well used for this little project.

Happyjo

alga
30th December 2009, 05:23 PM
I made myself some washing soda (sodium carbonate) by heating baking soda (sodium bicarbonate) in a stainless steel pot. It's weird to see dry powder boil, giving off gases.

Baking powder is a mixture of sodium bicarbonate and citric acid, it is too acidic.

Tatey
30th December 2009, 06:12 PM
I managed to buy 1kg of soda crystals from Tesco today for the grand sum of 97p :D, i'll be derusting my components tomorrow

davielad
5th January 2010, 08:31 PM
i believe you can use a higher voltage/amp to get fast/better results, therefore i am going to attempt to do it with my ark welder.

has anyone used the bath and welder setup?

Tatey
5th January 2010, 10:31 PM
Personally i wouldnt attempt to do it using an ARC welder. The power output is massive and if the current goes through you then it'll stop your heart, not worth it to save an hour at most....

aerosam
5th January 2010, 11:46 PM
Agreed - don't forget the hydrogen that is produced by the process, one spark and BANG!

I'm a big supporter of grit blasting rather than other methods for rust removal. CKC mag ran an article this month that said that it was unsuitable for components that are fragile or have extensive corrosion. Well, if the rust is that bad - would you really want to use that part anyway? Blasting gives instant results and leaves the part perfectly prepared for repainting. Although I should mention that it is critical that the part is given some surface protection within a couple of hours or rust will set in very quicly, as the process greatly increases the surface area of the part.

Machine mart sell a small cabinet for £118 but it realy is a worthwhile investment (provided you already have an air compressor). It can also be used with glass beads or walnut shell. If you have larger parts to clean, it may be worthwhile asking your local metal plating/galvanising/wheel restorer company for a quote to blast them for you.

Having said all that, electrolysis is a cheap method for doing a small number of small parts. And I guess we are all building a sports car, on a budget.