De-rusting project - Page 4

droopsnoot · 27-05-20, 05:41 PM

@Audi Stan, as you see in my image above, I have the workpiece connected to the negative side of a 12v power supply (in that case, a battery charger) and the positive connected to one or more pieces of plain steel. The electrolyte is plain water with washing soda crystals dissolved into it - I use a rate of 1 tablespoon per gallon of water. Making it much stronger doesn't have a significant effect on the performance.

Switch the battery on and you should see some activity in the water as the rust is electrolytically removed from the workpiece. The water will turn very dirty as bits come off it. The other pieces of steel will get dirty too, and will benefit from regular cleaning.

Don't use a galvanised bath or bucket as your container - apart from isolating the current, apparently that will give off some harmful gas because of the zinc coating. Something non-conductive is ideal, I'm using a 2.5 gallon plastic bucket at the moment. Use a container you don't care about - it will be filthy afterwards, and virtually impossible to clean. The bath in my photo was destined for the skip, so I borrowed it for a bit.

A lot of the cleaning action works on "line of sight", so multiple electrodes will help to clean the piece evenly. It's not cut and dried, but it does help speed things up.

Audi stan · 27-05-20, 08:16 PM

Massive thanks for the information, I intend to try this operation with several items , some off my Audi and many parts of an old French moped I have.
Looking for to trying it and like you mention, I'm not under any time pressure.��

jimh · 27-05-20, 10:42 PM

I've done this too and have an extra tip.

You can buy graphite rods from Amazon:-
https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1
If you use those as electrodes, the water solution stays clean, so you can see what is happening easier and you don't have a mess to deal with at the end.

Tun · 28-05-20, 07:19 AM

Would an industrial drip tray be suitable? there are lots of different sizes available.
https://www.tanks-direct.co.uk/spill...base-only.html

SorenR · 28-05-20, 09:41 AM

A tank pallet like this and cut the top off

???

droopsnoot · 28-05-20, 09:41 AM

Quote:

Originally Posted by jimh

I've done this too and have an extra tip.

You can buy graphite rods from Amazon:-
https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1
If you use those as electrodes, the water solution stays clean, so you can see what is happening easier and you don't have a mess to deal with at the end.

Oh, that looks interesting. Do they work as well as steel electrodes?

jimh · 28-05-20, 05:36 PM

Quote:

Originally Posted by droopsnoot

Oh, that looks interesting. Do they work as well as steel electrodes?

Yes. When I was done, there was just a small amount of graphite powder in the bottom of the bucket and the graphite rods were depleted maybe 1%

droopsnoot · 28-05-20, 06:34 PM

Great, I'll try those at some point.

(I was intending to come back and edit my post but I forgot. Of course they work as well as steel electrodes, because you'd have mentioned it otherwise, or just not suggested them.)

Hanuman · 05-06-20, 01:49 PM

Quote:

Originally Posted by droopsnoot

B&Q have something similar, though it's wider than you want. It was £20, so no good for me (as the track probably cost less than that, I just want to keep the dust off it and it won't fit properly in the old drawer it's in now) but was the only box longer than a metre. I can't remember whether it would be 1.2m though.

B&Q did have something- A Really Useful box, 1.2m long, takes the subframe/crossmember, and will probably be sufficiently tall enough to keep the item fully submerged. Good shout.

Now if I can just encourage my older battery charger to put out sufficient current.

I’ve used citric acid on a lot of stuff these last few weeks, but only got the long box a few days ago. I’ve ordered some graphite rods, too.

Stuff done with acid
1 vice
30+ old woodworking tools
About 20kg of chisels, bolsters, rasps and files of varying coarseness.
Some suspension joins/arms/brackets

Stuff to tackle- (Electrolytically in some case, acid in others.)
2 pairs calipers and carriers- vented disc
1 pair solid version
Set of ur struts from the Ur-
Pair of front struts from V8, another pair from the 100
Three cross members
4 Ur- wishbones
Various older Ur- track arms, joints, etc

tractor Dave · 06-06-20, 02:52 PM

Ok. I decided to give it a go.

Sent from my iPhone using Tapatalk

28-05-20, 07:19 AM	#34
Tun Grown up member Classic Audi Club Member Join Date: May 2011 Location: Buxton Posts: 745	Would an industrial drip tray be suitable? there are lots of different sizes available. https://www.tanks-direct.co.uk/spill...base-only.html __________________ 1988 MB quattro 2012 S4 Avant

27-05-20, 05:41 PM	#31
droopsnoot Grown up member Join Date: Jun 2015 Location: South Cheshire Posts: 212	@Audi Stan, as you see in my image above, I have the workpiece connected to the negative side of a 12v power supply (in that case, a battery charger) and the positive connected to one or more pieces of plain steel. The electrolyte is plain water with washing soda crystals dissolved into it - I use a rate of 1 tablespoon per gallon of water. Making it much stronger doesn't have a significant effect on the performance. Switch the battery on and you should see some activity in the water as the rust is electrolytically removed from the workpiece. The water will turn very dirty as bits come off it. The other pieces of steel will get dirty too, and will benefit from regular cleaning. Don't use a galvanised bath or bucket as your container - apart from isolating the current, apparently that will give off some harmful gas because of the zinc coating. Something non-conductive is ideal, I'm using a 2.5 gallon plastic bucket at the moment. Use a container you don't care about - it will be filthy afterwards, and virtually impossible to clean. The bath in my photo was destined for the skip, so I borrowed it for a bit. A lot of the cleaning action works on "line of sight", so multiple electrodes will help to clean the piece evenly. It's not cut and dried, but it does help speed things up.

27-05-20, 08:16 PM	#32
Audi stan Grown up member Join Date: Mar 2016 Location: Lancashire Posts: 36	Massive thanks for the information, I intend to try this operation with several items , some off my Audi and many parts of an old French moped I have. Looking for to trying it and like you mention, I'm not under any time pressure.��

27-05-20, 10:42 PM	#33
jimh Grown up member Classic Audi Club Member Join Date: Dec 2008 Posts: 122	I've done this too and have an extra tip. You can buy graphite rods from Amazon:- https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1 If you use those as electrodes, the water solution stays clean, so you can see what is happening easier and you don't have a mess to deal with at the end.

28-05-20, 09:41 AM	#35
SorenR Grown up member Join Date: Oct 2010 Location: Vesterlyng/Föllenslev, Denmark Posts: 563	A tank pallet like this and cut the top off ???

28-05-20, 06:34 PM	#38
droopsnoot Grown up member Join Date: Jun 2015 Location: South Cheshire Posts: 212	Great, I'll try those at some point. (I was intending to come back and edit my post but I forgot. Of course they work as well as steel electrodes, because you'd have mentioned it otherwise, or just not suggested them.)

06-06-20, 02:52 PM	#40
tractor Dave Senior Member Classic Audi Club Member Join Date: Apr 2018 Location: Wales Posts: 1,157	Ok. I decided to give it a go. Sent from my iPhone using Tapatalk