Iron cannons

Noora Hirvonen <noora.hirvonen [at] kolumbus__fi> writes

>I am seeking information to help me to determine the right
>conservation treatments for over hundred iron cannons that are
>located outdoors around Suomenlinna fortress

Prince of Wales' Fort near Churchill, Canada has a very similar
arctic, marine climate to Suomenlinna.  We are on the coast of
Hudson Bay and our latitude is just south of 60 degrees.  The fort
has 42  British cannon from the 18th century still standing on the
ramparts.

Robert Smith and Howard Wellman both make very good recommendations
for cast iron cannon, however, I want to add a word of caution.  We
have found through experience that coatings which work well in
southern climates do not always cure properly in the arctic and
sub-arctic.  Epoxy coatings in particular do not cure properly if
the ambient temperature drops below about 20 deg. C within 24 hours
after application.  There are "polar" formulations, but they do not
work very well either.  If possible, moving the cannon to an inside
workshop is the best environment to apply the coatings.  It also is
the easiest for containing the blast media, if you are using air
abrasion for cleaning.  A temporary enclosure with heating may be an
option, if the cannon cannot be moved.

For further information on our cannon project (what worked, what did
not work, and why), please refer to:

    Busse, E., "The Manitoba North Cannon Stabilization Project",
    Metal 95 Proceedings of the International Conference of Metals
    Conservation, Semur en Auxois, Sept. 1995, James and James Ltd.,
    London, 1997, pp 263-268.

    Croome, H.L,, "Corrosion rate study of cannon at the Prince of
    Wales' Fort", Metal 04 Proceedings of the International
    Conference of Metals Conservation, Canberra, Oct. 2004, National
    Museum of Australia, 2004, pp 195-206.

Liz Croome
Conservator Supervisor
Parks Canada


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                  Conservation DistList Instance 21:9
                   Distributed: Friday, June 8, 2007
                        Message Id: cdl-21-9-004
                                  ***