[AT] De-Rusting

[Mike Sloane]

I agree with Steve W. The electrolytic system doesn't care about paint, 
wood, rubber, etc. You can de-rust a hand saw with the wooden handle 
still attached, and it will still come out clean with no damage to the 
wood.

I use TSP (tri-sodium phosphate) for an electrolyte, and that also helps 
with the clean-up. It is available in almost anyplace they sell paint 
(it is primarily sold for cleaning masonry - use gloves when handling 
the solution, as it is pretty strong).

But it is still a good idea to do a little rough cleaning, just so you 
can see where you are going. The trick is to use a big enough container, 
provide enough power, and have anodes in the right place. I happen to 
like stainless steel for anodes, but some claim that it gives off 
poisonous fumes. Since I do all my electrolytic de-rusting outdoors, 
that has not been a problem. Regular steel anodes are much less 
efficient and also erode fairly quickly.

See <http://www.stovebolt.com/techtips/rust/electrolysis.pdf> for more 
information.

Here is my electrolytic system in action: 
<http://public.fotki.com/mikesloane/tools__equipment/derusting_tank1.html>

Mike

Steve W. wrote:
> Stephen Offiler wrote:
>> It's a bit of a stretch to relate this to old tractors, but I still
>> think it's a fitting topic.  Here's the situation:
>>
>> My boss lives on a 300-year-old farm in Massachusetts.  Recently,
>> while excavating in a corner that hadn't been disturbed in a long,
>> long time, they began to unearth some iron artifacts, some down as far
>> as 3' below ground level if I understood correctly.  A few of these
>> miscellaneous hunks of rust remind me of something that might have
>> been part of some old horse-drawn cultivator or something.  My task is
>> to clean them up a bit, with the intention of perhaps putting them on
>> display in his home if they appear interesting enough.
>>
>> They are heavily encrusted with rust and a fair amount of soil.  I
>> started thinking about sandblasting or tumbling (because we have that
>> equipment here at work) but then I started thinking electrolytic
>> de-rusting instead.  I am looking for comments from anybody who's been
>> there, done that... and that would be pretty much every antique
>> tractor enthusiast, wouldn't it?
>>
> 
>> - if I go the electrolytic route, how much pre-work should I put into
>> them before they go in the tank?
> 
> Not much the bath will take off most of the rust and scale for you.
> 
>> - how to pre-clean them, soap and water, mineral spirits, mechanical
>> means such as wire brush, sandblast, etc?
> 
> Got a car wash nearby? Take them in there and blast them clean of the
> dirt and any loose crud. Whack them a few times with a hammer to knock
> off any large loose chunks of rust.
> 
>> - is electrolytic the best choice?
> 
> Yup.
> 
>> Thanks,
>> Steve O.