Varnish for painted metal

We are currently commissioning treatment for an external, painted
metal object. The object is to be partially repainted and it has
been recommended that we seal in the layers and protect the paint
with "Blackfriar Yacht Varnish".  On contacting the manufacturer we
have discovered that the varnish is comprised of a blend of alkyd
resins (long oil alkyd resin and a polyurethane-modified alkyd
resin) and a UV absorber.

Does anyone have any experience of using this varnish?  We are
particularly interested in its long-term ageing characteristics.  Is
there an alternative resin that could be recommended for use as an
external coating on painted metal?


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                  Conservation DistList Instance 21:43
               Distributed: Wednesday, February 13, 2008
                       Message Id: cdl-21-43-017
                                  ***