[meteorite-list] Stopping Rust & Preserving Iron Meteorites - THIS WORKS!

From: Steven Schoner <american_meteorite_survey_at_meteoritecentral.com>
Date: Thu Apr 22 10:08:27 2004
Message-ID: <20020918142252.47488.qmail_at_web11403.mail.yahoo.com>

And I might also add that the process that I devised
also works well with Brahin. But with pallasites one
has to be careful as some of the olivines have a
tendency to rise out of their sockets as the FeCl3 is
converted to FeOH. Then during drying the FeOH is
converted to iron oxides. And the olivines are at
this point fairly secure. But what I do is use
superglue to fix all the olivines then sand it down.
I then leave the pallasite slices uncoated after
polishing for several weeks. If they don't rust then
I heat them to 150 degrees then dip them in
polyurethane and allow them to dry.

They never rust again.

The process also works very well with the problematic
Lamont mesosiderite as well.


Steve Schoner
American Meteorite Survey.

 
--- Jeff Kuyken <jeff_at_meteoritesaustralia.com> wrote:
> G'day List,
> A couple of months ago I wrote to the list asking
> for help to stop my Chinga slice rusting. There have
> been a few posts since then asking similar questions
> so I thought I would share this with everyone.
> Before I continue, I really need to mention that the
> problematic 111g slice of Chinga arrived to me
> rusting in a way that would have put any Nantan to
> shame! John Gwilliam replied to my post with a great
> process that I have tried and has worked extremely
> well. Thanks John. It has been several weeks now and
> not even the slightest hint of rust has reoccurred.
> I have included the post below.
>
> Thanks,
>
> Jeff Kuyken
> I.M.C.A. #3085
> www.meteoritesaustralia.com
>
> "Hello Jeff and List,
>
> According to Ivan Koutyrev, all the Chinga irons
> they have found have been
> recovered in stream beds. This means that the irons
> have been in almost
> constant contact with water for a long time. Over
> hundreds of years, rust
> has been able to migrate into the interior where it
> can be a chronic
> problem if not treated properly.
>
> After the meteorite has been sliced, I sand down the
> flat surfaces starting
> with a 100 grit or even a fresh 220 grit sanding
> belt (on a water cooled
> lapidary sander). Successively finer grits are used
> until I'm down to a
> worn 600 grit belt. Remember to wash the iron slice
> and rinse in anhydrous
> alcohol in between every grit change so you don't
> have a stray piece of
> larger grit mess up your polished surface. After
> the worn 600 grit
> polish, I treat the specimen for 5 - 10 days in the
> alcohol/ sodium
> hydroxide bath recommended by Steve Schoner. This
> will attack the rust in
> the specimen and the sodium in the mix bonds with
> the chlorides in the rust
> and becomes common salt. Believe me, this solution
> really works. I have
> several slices of OLD Campos sitting unprotected out
> in my shop that were
> treated over 18 months ago and none of them show a
> hint of rust. For those
> of you interested in this process, I think you can
> find it on Eric
> Twelker's website.
>
> After soaking in the bath, I rinse the specimen
> thoroughly in FRESH
> anhydrous alcohol and wipe it dry.
>
> Next, I polish the slice with a muslin buff on a
> jewelers spindle. My
> polishing unit has dual 6" x 1" stitched cloth
> buffing wheels that you can
> mount on any motor with an arbor or spindle. My
> machine turns at 3,250
> RPMs but a slower motor in the 1,720 RPM range will
> work as well. The key
> to the final polish is the compound applied to the
> moving buff. I use a
> product manufactured for the jewelry industry
> called ZAM. I believe it
> contains chromium oxide as the polishing agent. It
> is a light green hard
> stick in a cardboard wrapper and is available from
> jewelry supply outfits
> and some lapidary shops. Several minutes of
> polishing will produce that
> mirror like polish you are looking for."
>
>


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Received on Wed 18 Sep 2002 10:22:52 AM PDT