[meteorite-list] Meteorites and Humidity: Some Questions

From: John Hendry <pict_at_meteoritecentral.com>
Date: Sat, 6 Mar 2010 10:32:45 -0700
Message-ID: <001301cabd53$09d6d590$1d8480b0$_at_co.uk>

These may be daft ideas or already tried, but apart from dessicant removal
of moisture what about another line of attack...

(1) Removal of oxygen from the container... fill it with argon or nitrogen

(2) Scavenge oxygen from the container. The food industry deploys scavenger
sachets to remove oxygen from packaging and the most popular seem to be
sachets of iron filings. Probably these will oxidise quicker than the
meteorite given the larger surface area and absence of nickel.

http://www.nitro-pak.com/product_info.php?products_id=366

(3) UV activated scavenging polymers exist but these seem designed for final
depletion of an already low O2 atmosphere <2%. Might work in conjunction
with (1).

http://www.sealedair.com/products/food/os/oxygen_scavenging.html

(4) Use zinc as a sacrificial scavenger. Perhaps pack a perforated
non-conducting false bottom to the container with zinc wool thus isolating
it from contact with the specimen.

(5) Treat the specimen with vapour phase corrosion inhibiters. This will
form a molecular film on the specimen so I'm not sure of whether there would
be any alteration in the visual appearance of the specimen, or any other
undesirable side effects.

http://www.agmcontainer.com/vci/index.htm
http://www.agmcontainer.com/vci/vci_faqs.html

Regards,
John


-----Original Message-----
From: meteorite-list-bounces at meteoritecentral.com
[mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Marco
Langbroek
Sent: March-06-10 3:11 AM
To: meteorite-list at meteoritecentral.com
Subject: Re: [meteorite-list] Meteorites and Humidity: Some Questions

> I store them primarily in Riker boxes and some in the jewel cases they
> arrived in. I live in north central Florida and except for my air
> conditioned home, I don't have the meteorites in any other climate
> controlled container or cabinet. I'm noticing a few of the irons
> (Miles especially) and one or two of the stony irons to appear a
> little rustier than when they arrived.

I am actually not so fond of Riker mounts. Maybe it is our Dutch climate,
but I noted specimens start to rust on the contact face between the Riker
glass and the stone/iron: probably because moisture condenses there and/or
gets trapped.
This was while there was dessicant in (some) of the mounts.

The problems vanished once I got myself a glass display cage. My meteorites
are much more stable now.

- Marco

-----
Dr Marco Langbroek - SatTrackCam Leiden, the Netherlands.
e-mail: sattrackcam at wanadoo.nl

Cospar 4353 (Leiden): 52.15412 N, 4.49081 E (WGS84), +0 m ASL
Cospar 4354 (De Wilck): 52.11685 N, 4.56016 E (WGS84), -2 m ASL
SatTrackCam: http://home.wanadoo.nl/marco.langbroek/satcam.html
Station (b)log: http://sattrackcam.blogspot.com
-----
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Received on Sat 06 Mar 2010 12:32:45 PM PST