Tin pest

This is another later reply to the matter of tin pest which has been
raised recently.

The information from a Russian publication suggesting that Scott's
fuel supplies on the polar plateau in Antarctica were due to failure
of the tin solder due to tin pest is at variance with information in
Roland Huntford's book on Scott and Amundsen.  Huntford claims that
it was poor quality soldering which was responsible for loss of
fuel, not deterioration of the solder itself. Any hole, or even
porosity in the solder, would be particularly problematic in this
instance due to the altitude on the plateau (around 2500 metres).  I
personally think this is a more likely explanation- but it might be
possible to confirm this since I think that several of the fuel
containers are held in collections at the Canterbury Museum at
Christchurch, New Zealand.

In four different visits to historic buildings in Antarctica I have
seen many tin cans from 30 to over eighty years old: most of the
underlying steel had rusted but the tin plating was still bright
where it had not worn off.  These objects would undergo frequent
temperature change through a range from around -35 degrees C
(typical winter minimum) to a surface temperature in the + 20s
Celsius, so if tin pest is going to occur it should be visible on
these objects.  The fact that no powdery grey  tin is observed
suggests that 'tin pest' may be confused with some other form of
corrosion, such as from volatile organic acids.

Janet Hughes
National Museum of Australia
GPO Box 1901
Canberra ACT 2601  AUSTRALIA
+61 2 6208 5253
Fax +61 2 6208 5299

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                  Conservation DistList Instance 12:40
                 Distributed: Monday, November 2, 1998
                       Message Id: cdl-12-40-005
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