Buried metal

Jack Ogden <jack [at] striptwist__com> writes

>There are sometimes minute, very fragile meandering tubes on ancient
>buried metal objects that I have always thought of as 'worm casts'
>(though that might not be the right term). ...

>From the description of the patterns you have observed the
phenomenon could be filiform corrosion, also known as "worm track"
corrosion. They are a well recognised form of activity in the field
of corrosion science, occurring most often under films or coatings
although filiform corrosion has been recorded on non-coated objects.
There has been quite a bit of research into filiform corrosion on
aerospace aluminium but less work has been published in the
Conservation literature.

A Studies in Conservation Article discusses the problem: Volume 42
No. 1 (1997)

    "Problems with coated silver: whisker formation and possible
    filiform corrosion"

    Catherine Sease, Lyndsie S. Selwyn, Susana Zubiate, David F.
    Bowers and David E. Atkins

Deborah Lau
Analytical and Conservation Scientist
CSIRO MIT
Gate 4, Normanby Road, Clayton, Victoria, 3169
Private Bag 33, Clayton South, Victoria, 3169
+61-3-9545 2830 mobile: 0418-24-8080
Fax: +61-3-9544 1128


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                  Conservation DistList Instance 18:8
                 Distributed: Wednesday, July 21, 2004
                        Message Id: cdl-18-8-006
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