Andy,

Thanks for all that. I'll try it out on something modest in size and go from
there.

Cheers

John G


"Andy Dingley" wrote in message
news
On Wed, 09 Feb 2005 18:15:37 GMT, "John G"
wrote:

Your solution seems easier than acquiring a horse to shoe, but all I get
on
electrolysis from google is info on dealing with nasal hair. Any further
clues?

Try searching for electrolytic derusting
or try
http://www.stovebolt.com/techtips/ru..._derusting.htm


Take a bucket. Doesn't need to be huge, because you can do big things
in sections and rotate them around.

Find a battery charger. 12V, moderate current, dead simple. You may
have problems if you try it with an "automatic" charger. An ammeter
is helpful, but not essential.

Make an electode clamp for the workpiece. Most things can just use the
battery charger's croc clip, but an anvil could be tricky. Get a good
connection.

Insert anvil into bucket.

Insert other electrode (anode). This should be a big piece of
unpainted steel, maybe stainless steel. Don't use galvanised. Bar or
sheet is OK, so long as you have enough of it. Rusty is OK. Surface
area should be "comparable" to the workpiece. Stainless steel lasts a
very long time, plain steel will disappear at about the same speed as
the rust.

Arrange the two electrodes so that they're separated. Like
electroplating, it's a "line of sight" process, so expect to have to
re-arrange things over time. You can also use multiple anodes, simply
paralleled together with jump leads.

Pour in the electrolyte. This is water and washing soda, about "a
handful to a bucket" strength. Throwing in the soda and pouring a
kettle over it is all you need to do about carefully mixing it. Don't
use sodium hydroxide / caustic soda or baking soda - washing soda is
the stuff, and it's cheap and easy to find (50p/bag from Wilkinsons or
Tesco)

Connect the electrodes. BLACK NEGATIVE ON THE THING YOU'RE KEEPING.
Red on the anode that you will destroy.

Power on. A good setup will use an amp or so, maybe a few amps for
somethign the size of an anvil. If you don't get this, check the
connections, check the washing soda strength and try re-arranging
things in the bucket. Sometimes it takes an hour to get going, by
which time you should see some gas bubbling from the electrodes. The
current won't flow well through paint, but will lift paint eventually.

Now leave it. Check back every few hours / days. An anvil will take a
few days on each side at least. Re-arrange things to do the other
faces.

If the tank "froths", it means that something in there was greasy and
the soda has turned it to a crude soap. Remove the scum as needed, but
don't worry about it.

Immersing the croc clips will give a greenish coppery scum - don't
worry about it. Immersing the anode's clip may damage the wire and the
clip, so try to avoid that.

As the rust is removed, a black sludge builds up. After a while, this
becomes a rust-red sludge. Remove it with a big spoon when it
threatens to fill the tank.

When completed (bare metal) the process stops by itself. It's safe to
leave this running indefinitely - the great advantage of this process
over all others.

Keep the tank topped up with plain water, owing to evaporation and
electrolytic losses. Add more washing soda to replace spillages.

When you remove the cleaned metalwork, it will be _very_ clean and
bare. Dry it carefully and immediately and wax polish or WD40 it -
left bare it will quickly rust again, but this is just a bright orange
light rust and comes off easily anyway.
--
Smert' spamionam