Hello OleTruckers,
Thanks, Mark, for spearheading the rust removal discussion: very interesting.
Stovebolt dot com http://www.stovebolt.com/ has an article:
"Electrolytic Rust Removal: by Ted Kinsey. He presents an alternative to those
of us
contemplating driving our OleTrucks into the neighbor's pool, or the Gulf of
Mexico. (Is rust removal what the Coast Guard was attempting when they sunk the
Cuban Amphi-AD?) He suggests using an electrolyte wetted sponge with a
backing electrode to clean spots on large objects or things that shouldn't be
submerged.
He also mentions (I suppose for those times when the power grid misbehaves)
using Coke-Cola to remove rust. Before dentists used stainless steel for
braces, did they gave Coke to patients to control rust?
Further info on hydrogen embrittlement (as it affects zinc plating) can be
found at:
http://www.finishing.com/2200-2399/2278.html .
It's not surprising your steering arms aren't made of hardened steel. I don't
know much about hardened steel, except, it is brittle. When it fails, it
fractures fast and dramatically--like my continually knocking chips out of my
cold chisel's cutting edge. Mild steel is softer. It bends and mushrooms before
it fails, giving advance warning that it is time to repair or replace. I'd be
hard pressed to chip a mild steel 16 penny nail the way I chip my cold chisels,
unless it happens to be a really cold Minnesota winter day, when even Chevy
AD's won't start, and when a rubber band will shatter when dropped to the shop
floor. I don't know what steel is in steering arms, but I am happy it's not
hardened.
Regards, keep up the good work, and drink Coke for a rust-free mouth,
Culver Adams
1951 Chevy 3100, still above freezing in Minneapolis
---
In a message dated 10/27/03 9:28:51 PM Central Standard Time, mark@noakes.com
writes:
<< Subj: [oletrucks] Further adventures in rust removal
Date: 10/27/03 9:28:51 PM Central Standard Time
From: mark@noakes.com
Sender: owner-oletrucks@autox.team.net
Reply-to: mark@noakes.com
To: virtualvairs@corvair.org, oletrucks@autox.team.net,
napco4x4@yahoogroups.com, Old-Burb-club@yahoogroups.com
After my prior post on electrolytic rust removal, I got a few more
suggestions and a
couple of challenges as to how safe this technique is from various lists and
so did some
more checking with the following comments. The most important thing to note
is I'm just
a hobbyist like you guys exploring what my options are and reporting
results; I'm not a
professional in this field. Treat the info accordingly.
1--White Vinegar can also be used to clean some rust; I haven't tried this
one but
others have reported that it works. It shouldn't have any negative effects
per below.
2--A more thorough treatise on electrolytic de-rusting can be found at:
http://www.htpaa.org.au/article-electro.php
For some reason, I couldn't get the whole document to print though. If you
intend to
try this technique, read that whole article.
3--There is one major concern with electrolytic cleaning and that is hydrogen
embrittlement. ShopNotes (my experiment reference) didn't mention it at all
(but in all
fairness, their interest was in cleaning tools), but the site in item 2 does
even though
they treat it mundanely. After a comment from one email that I had ruined
my steering
arms, discussing this issue with a PhD metallurgist specializing in hydrogen
embrittlement and a little further study, I came up with the following:
* The issues are embrittlement of the metal due to hydrogen takeup and
possible stress
cracks from hydrogen buildup in the material around internal defects in the
object.
Hardened steel tends to be susceptible; softer material is not usually.
* Hydrogen embrittlement is temporary. it will go away on its own after a
few weeks or
can be removed by heating the treated object to about 160C for about 14
hours.
* Obviously the stress cracking that may occur during hydrogen embrittlement
would be
permanent and could lead to catastrophic failure of the object, hence the
reason for not
using this technique on safety-related items.
* Sodium bicarbonate electrolytic cleaning is mild and would not normally be
a problem
on any steel for an hour or so. However the effect is time, material, and
electrolyte
dependent; at the very least, hardened steels should not be treated for
extended
periods.
* Final suggestion is don't use this technique on hardened steel such as
springs and
restrict use on any high strength steel components...such as steering arms
(oops!),
suspension components, etc. Stick to good old sandblasting for hardened
steel. The
electrolytic technique is fine for non structural items or anything that is
not high
strength steel. Of course, my interest in this technique was that I didn't
have a sand
blaster, and I have had parts damaged by over zealous commercial blasters
that I have
taken parts to.
* Since I had already treated my steering arms, one suggestion to determine
hardness
was to use a file on a safe portion of the object. If the file can readily
remove
material, then the object is relatively soft and was probably not affected.
The file
cut into the one I tried fairly easily...shouldn't these be pretty hard?
I'll probably
see if I can get them tested at the local university metallurgy lab to see
if they are
ok. The only way to be sure is not to electrolytically treat critical parts.
4--I tried another experiment, this time with the center mount tail light
assembly from
a 50s era Suburban tailgate; these are very rare and I have managed to
collect two
complete units plus most parts for a third. This particular unit had heavy
rust inside,
so much so that I couldn't even begin to work the nuts on the internal screw
studs to
take things apart to restore it. Sandblasting would have ruined it. I put
it in the
bath for about 12 hours and it reduced the rust about 80%, to the point
where I can
work with the internal parts. I'll disassemble it as much as possible and
and then dunk
the subassemblies that need it again. There are no structural issues with
this part so
the dunk time is not an issue. This is the kind of cleaning task for which
the
electrolytic technique is perfect.
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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