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Lawrence A. Ramsey
 
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Default Varnish Finish Failure

Just out of curiosity, I wonder if a water-based polyurethane would
hold up? I know the Spar varnishes have a long chain which enables
them to stretch more and be more resistant to UV. Since boat builders
us Spar, I guess that may be way to go. Still, I wonder??? Hydrocote,
Resistane


On Mon, 24 Nov 2003 21:57:07 -0600, "Joe Nation"
wrote:

I built a park bench out of white oak. I wanted to prevent the oak from
changing color due to weathering and finished it with a water based marine
grade UV stabalized varnish. The bench has been exposed to direct sunlight
and rain for about 4 months and it is apparent that the varnish is not
preventing moisture from getting under the finish. The oak lumber in a lot
of places is begining to change colors. The color change is greatest in the
part of the white oak lumber that has small pores exposed to the surface.
The varnish remains attached to the entire surface and shows no signs of
pealing. What can I do to this piece to preserve its original nonweathered
oak color. Is there a marine spar varnish that will protect the oak and
prevent a change in its color? Can this bench be recoated with a spar
varnish that will stop any future color changes to the wood?

I googled on spar varnish and did not find much help with this problem. Any
help you can give me would be appreciated.