[meteorite-list] Re: Dronino & Steve Schoner's meteorite anti-rust treatment.

From: Norm Lehrman <nlehrman_at_meteoritecentral.com>
Date: Mon Jan 23 22:42:11 2006
Message-ID: <20060124034205.66856.qmail_at_web81001.mail.mud.yahoo.com>

Mike & list,

I haven't seen any responses come through on this and
it's a bit of meteorite lore that many might find
occasion to need. I don't know anything about the
Schoner post you mentioned, but last year I had a
chance to go to Argentina and acquire some Campos
directly from the family who's estancia includes part
of the strewn field. They have recovered more than a
tonne from the family garden plot!

This is an extreme case, and for lesser rust you can
be less aggressive. The pieces I got were very rusty.
The locals coached me on cleaning them, and this
approach worked very well.

1) pound all the scaly areas with a hammer. It sounds
brutal, but you won't be able to mark the solid metal
(remember the Tucson ring/anvil!). Only the scaling
rust will flake off, and you need to get rid of it. I
used my geologist's pick. The pointy end works well
for getting into regmaglypts. Spend some energy at
this stage. I was stuck in a field camp in the high
Andes, so I pounded on my meteorites every evening for
a couple of weeks. Rust everywhere! This is an
outside job.

2) Immerse it in a strong sodium hydroxide solution
for as long as it takes. Two weeks is common, a month
is not uncommon. You will see an amazing amount of
rust flakes spall off and fall to the bottom. After a
couple of weeks transfer the iron to another pail and
decant the lye solution onto it. When stuff quits
falling off, you're done. You will lose some mass,
but this story is about a real rust bucket, and
anything that will come off by this process needs to
come off.

3) Rinse it well. I used water, and I really think
it's okay at this stage. Anything that was porous or
cracked will have come off in steps 1 or 2. You need
to get rid of the lye. You can deal with the water in
step 4.

4) Immerse in anhydrous isopropyl alcohol for about a
week.

5) Air dry, then dry in the oven under low heat, oven
door cracked open for an hour or so.

6) While it's still warm (but no longer hot) treat
with a rust inhibitor. The Argentines suggested
simple mineral oil, which I used with fine results. A
thread on the metlist a year or so ago recommended
Paraloid dissolved in acetone (used for conservation
of archaeological materials). Type B72 for irons, B42
for stones.

Hope this helps someone out there.

Cheers,
Norm, squirrely as a first-grader on the day before
Christmas!!! Heading for Tucson the day after
tomorrow---
(http://TektiteSource.com)

--- Mike Fowler <mqfowler_at_mac.com> wrote:

> (Don't know if this made it thru the other day)
>
>
> Hi List,
>
> Went to my local hardware store to buy Red Devil
> Lye, but couldn't
> find any so I bought some (where else!) on ebay. I
> will be trying it
> out on some smaller irons that show some rust,
> including at least one
> Dronino.
>
> I was curious about Steve Schoner's 150 lb Campo
> mentioned in the
> post from November, 2003. Was the treatment
> successful, and what are
> the details? How long etc?
>
> I have one 13 lb Campo that could use a little help
> after I practice
> an a couple 100 gram slices first.
>
> Mike Fowler
> Chicago
>
> Bob King's post regarding Dronino:
>
> > Hello Bernd, Marcin and all,
> >
> > I, too have had problems with Dronino until I used
> Steve Schoner's
> > NaOH method. I left my slice in solution in a jar
> for two weeks.
> > Every so
> > often I'd pick up the jar and swirl the contents
> around to keep the
> > chemicals mixed and monitor the process . The
> solution gradually
> > became as dark as maple syrup as rust was
> dissolved. Then I removed
> > the slice, washed it in distilled water (the lye
> makes the pieces very
> > slippery.) and baked it in the oven for an hour at
> around 200 degrees.
> > I still keep my Dronino with dessicant but I have
> not seen a speck of
> > rust since this treatment.
> > Marcin, you asked about dissolving the lye. I fill
> the jar halfway
> > with
> > regular isopropyl alcohol (off-the-shelf drugstore
> variety) which
> > contains
> > water. Then I add about 5 tablespoons of lye (Red
> Devil brand here in
> > the U.S.) and stir and stir. It takes a while for
> the lye to
> > dissolve in the
> > alcohol. While this is happening you get an
> interesting exothermic
> > chemical reaction and the jar warms up.
> > Anyway, this is the only thing that's worked for
> really stubborn
> > irons.
> > Best to all,
> > Bob
> >
>
>
>
> Post from Steve Schoner, November 2003
>
> > <s.gif>
> >> By popular request, and a huge amount of e-mails
> regarding it, I post
> >> it now and for as long as the internet exists at:
> >>
> >>
>
http://www.geocities.com/american_meteorite_survey/naoh.htm
> >>
> >> You can post it anywhere, share it, distribute it
> widely, and do so
> >> with the intent of preserving stubborn rusting
> meteorites that would
> >> otherwise snap crackle and pop as they flake away
> on the shelves,
> >> keeping
> >> one awake at night in the never ending cycle of
> terrestrialization.
> >>
> >> This "anti-rusting" process will help slow that
> down so that we can
> >> enjoy our specimens a bit longer.
> >>
> >> Currently I am soaking a 150 lb Campo and it has
> been in solution
> >> for 7
> >> months. Soon I will take it out and see where it
> is in the process.
> >> It is the largest meteorite I have ever done in
> this process.
> >>
> >> Some meteorites might not respond, but most do.
> >>
> >> Steve Schoner
> >>
> http://www.geocities.com/american_meteorite_survey
>
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Received on Mon 23 Jan 2006 10:42:05 PM PST