I know what your thinking.. You think
I've gone off my nut - removing rust with electricity?! Obviously
he's lost his mind... WRONG! Rusting is an electrochemical
reaction between the iron in steel and oxygen in the air - they bond
quite readily with each other. Here's the trick: you can use electricity
to break the bond of Iron Oxide to render it back into it's component
parts. Sounds neat, huh? Right now, your thinking "What's the
catch?" Mebbe it readily destroys good solid metal if your not
careful? WRONG! It only attacks rust, not live steel, something
that can't be said of other methods , like Naval Jelly. It must use
nasty chemicals then, right? WRONG! The only chemical used
is plain ole' laundry soda (not soap). Although you
can use the much more toxic lye in it's place, but if it's available(and
it is, Check out Arm and Hammer in the clothes detergent aisle), why
would you use it? Then it must use special equipment? WRONG!
A plain ole' battery charger is the only piece of equipment you need,
along with an electrode - I suggest using rebar.
Let's
get down to business...
The Solution:
The chemical solution is nothing more than laundry soda and water
at a ratio of one teaspoon or so to a gallon of water. Don't bother
adding more than is necessary, it doesn't work any better and it just
wastes money - the electricity does the work. I recommend using Arm
& Hammer laundry soda. The solution doesn't go bad, but after
a while it will get real scuzzy from the accumulated detrius in it.
Until it gets really skanky, you can keep reusing it, just continue
to add water as needed due to evaporation.
The Container: The
solution container can be anything as long as it's non conductive
and large enough for solution to circulate around the object. plastic
5 gallon "joint compound" buckets from places like Home
depot are cheap, good sized and can be used with a lid to cut down
on evaporation when not in use. For bigger objects, things like old(non
leaking) kiddy pools or even building a temporary tank using sheet
plastic works too. A good idea for long, narrow objects is plastic
window boxes without drain holes. The sky's the limit.
The Power Supply:
To make this work, your going to need a source of DC power. There
is no exact formula for figuring power requirements, but rather a
bit of simply logic : The more power you supply for a given object,
the faster the process works, conversely, the bigger the object the
more power you need to work in the same amount of time, and finally
the bigger the object for a given amount of power, the longer it will
take. That said, a 10 amp battery charger is fine for something
that will fit in the 5 gallon pail, if you want to do this on larger
objects on a regular basis, I suggest getting one of those hi ampage(200+)
chargers available from
Northern Tool.
They have a 200 amp model for $120 bucks. I wouldn't recommend buying
it for this if your not going to be doing big stuff regularly.
The Electrode: My
suggestion for the electrode is to use common rebar, with the idea
of having as much surface area of the electrode in solution as the
part being done. Some people are using Stainless Steel bar with the
thinking that it lasts a very long time - DON'T DO IT! While
it does last, it also releases Chromium into the solution, a very
toxic heavy metal. God help you if the local DEP catches you dumping
it. The rebar will get eaten away over time, but it's so cheap as
to make it a no brainer.
The Process: It's
simple - take the part, attach a wire of some sort (the bigger the
better, you may want to attach multiple wires - the wires art to keep
the charge leads out of the gunk) attach the lead to the wire and
attach the other lead to the electrode. Polarity is important! The
electrode must be hooked up to the POSITIVE(red; +) terminal
and part connected to the NEGATIVE (black; -) terminal. Also
make sure the electrode isn't touching the part, if it is, the rust
won't go into solution. Now that you've hooked everything up, go back
and double check everything, I'll wait... Done? Everything right?
Good, lets continue. With everything hooked up it's time to flick
the switch. Nothing much will happen. You may see fine bubbles coming
off the part. Don't worry if you don't. The only way to tell for sure
if it's working is to check the meter on the charger. If the juice
is flowin', it's working. Now comes the hard part: waiting. This process
may take anywhere from an hour or so to a day or more. It all depends
on how much rust, how big a part, and how much power you have. The
idea is to turn the juice off, take the part out and check it every
once in a while. If it looks like it needs more, do it, you can't
hurt it. When the scuzz starts developing on the surface of the solution,
just skim it off and continue - just make sure you either turn off
the juice or use something non conductive. When it's finally done,
turn off the power, take out the part, rinse off the solution in tap
water and give it a light rub with steel wool if it still has stuff
clinging to it. Use your own discretion when doing this. Last: protect
the metal right away as now that it's been cleaned of rust at the
atomic level, it will rust very quickly.
Links:
Here's a couple of links
about this process -
Automotive
resto using electrolysis
Using
a home made tank and a DC welder to derust a trailer frame
