Electrolysis

[The Bear]

I read a thread on this recently but can't find it now

I fancy a go at this. Most people seen to use some form of 12v dc supply. Does it matter how many amps the supply is?

Cheers

Mark

 

[Spindle]

Hi

Just search for rust removal by electrolysis on the web, it will throw up hundreds of hits - one below

http://antique-engines.com/electrol.asp

Depending on the item I'm treating I use either a phone charger, (small items, pliers, callipers etc.) or a car battery charger, (planes and larger). The battery charger usually registers about an amp draw during the process.

Regards Mick

 

[AndyT]

I've read a few threads as well and had a first go at it a few weeks ago.

I used an old 12v car battery charger, rated as being able to supply up to 5 amps and its meter showed that it was supplying 2-3 amps when in use. This was with single small items (a plane lever cap, cap iron and blade) in a small plastic box with some old steel tube at each corner. I believe that the actual current drawn will depend on the surface areas of your rusty item and your sacrificial anodes, and the distance between them.

My charger is an old, simple one with just a thermal cutout to protect against too high a current drain. I've read complaints that if you go and buy a new charger it will have electronic controls which make it less suitable, but I've no experience of that.

I know that lots of people are very enthusiastic about electrolysis but I did not like it much.
It's very messy - the water soon filled up with a foaming brown sludge which made it impossible to see what was going on. The actual rust removal effect was no better than using citric acid which is what I have mostly done in the past.

 

[Baldhead]

There are several videos on YouTube, I too fancy trying it, can you let us all know how you get on please.

BH

 

[JakeS]

I know that lots of people are very enthusiastic about electrolysis but I did not like it much.

IMO the best thing about electrolysis is that once you've set the bath up for it, you can do it with all kinds of things, not just use it for rust removal.

I've used an off-the-shelf disposable lantern battery for 'etching' a fairly large design in copper plate before, I imagine removing rust wouldn't be any different. Obviously a PSU would be better if you happen to have one, but... really, I'm pretty sure the only thing that matters is that the voltage is high enough to overcome the resistance of the medium. After that the current only determines how fast it happens.

 

[bugbear]

Here's a "get 'er done" write up:

http://www.fordmuscleforums.com/other-a ... lysis.html

Here's a slightly more thoughtful archaeology/conservation approach:

http://myweb.tiscali.co.uk/andyspatch/rust.htm

If there's a risk of direct item/electrode contact, this stuff looks helpful (it's the plastic mesh
pubs use to separate glasses from shelves)

http://www.swiftcateringsupplies.co.uk/ ... 17&scid=21

BugBear

 

[The Bear]

Thanks guys, I've already read several articles from the web but nothing that told me about the current.
I have nothing suitable as the power supply so need to get something and only want to spend a few quid on that, hence checking what I buy is suitable. I had been wondering about using a 12v transformer of the type used to charge small electrical appliances (essentially a large black plug, lead and jack plug on the end) but think I now need more amps than this would supply.

Mark

 

[Racers]

Hi mark

I would go for an old car battery charger from a car boot sale.
I used my "knocked up from stuff from the skip" one when I tried it.

Pete

 

[thick_mike]

For small items I used an old phone charger. Cut the plug off (that goes into the phone) and connect the exposed wires to crocodile clips. I bet you have an old phone charger at the back of a drawer somewhere...you could get it now and have a go...go on...go on!!

For a bath I used a milk carton jug with the top cut off and used a bit of old tin can as the anode. Make sure you abrade the surface of your anode to get a good connection. I don't think the anode material plates onto the cathode anyway, so it doesn't really matter what it's made from. You will end up with a passivated surface covered in black iron oxide, which isn't as attractive as the finish you get with chelating rust removal. But it works fine for removing rust even though it is a bit messy.

 

[The Bear]

Old phone charger is what I was thinking. But not sure it will have enough power for a no7 plane body

Mark

 

[graduate_owner]

Apparently battery chargers can give an output which is not a 'clean' DC, but fluctuates. An improvement is to use the battery charger connected to a car battery, as this combination gives a steadier output, and keeps the battery charged at the same time - so I've read. I haven't tried it myself.
I did get as far as cleaning out an old plastic dustbin and filling it with a solution of washing soda. That's about it so far. One of these days!!

K

 

[graduate_owner]

I forgot to mention, don't use stainless steel as the anode - you get poisonous chromium compounds produced. Just use unwanted plain old iron / steel bits.

K

 

[thick_mike]

Old phone charger is what I was thinking. But not sure it will have enough power for a no7 plane body

Mark

The current doesn't need to be very high as long as you keep the anode close to the cathode. If it doesn't do the whole thing in one go, just do half...the move the anode and do the other half. It's honestly not difficult. You can go from having nothing to having a go in half an hour.

I did some small bits (old auger bits) in an old mushy pea tin. Just gave the inside of the tin a quick sand with 60grit, then put a plastic milk bottle top in the bottom to insulate the auger bit (cathode) from the can (the anode), then filled the can with warm water and added half a teaspoon of bicarbonate of soda.

 

[andersonec]

I used a battery charger set to 12 volt, worked a treat, the longer you leave it the more rust it removes, I left mine overnight and the result on a very rusty old smoothing plane was very surprising. Four steel rods wired together and spread round a bucket, just make sure the positive terminal is connected to the rods.

Check Youtube for some videos.

Andy