Keith penned:
"Duh, there are lots of polyurethane varnishes out there. Since that
seems to be what is on your boat, stick with it. If you want to change
to spar varnish (and why would you?) sand down to bare wood and put on
a minimum of 8 coats, letting them dry and lightly sanding in between.
Personally, I use Honey Teak and love it. A bit of work to put on, but
very durable and only requires a maintenance coat or two of their
clear every year."

Keith,
Varnish is varnish, but poly is poly. Varnish can be had with UV
inhibitors, but indoor poly cannot. So far I haven't found any poly that
would match the original color and texture (satin) and have UV
protection. The exposed teak had indoor poly on it. It caused a nasty
white-ish/yellow-ish crusty look and feel to the wood that was exposed
(less than 2 seasons in the N. East). As I've said, I want to be able to
protect the wood, AND match the color of the original if possible. Poly
is a major PITA to keep up when weathered. Varnish, like you've pointed
out is comparatively fairly easy and with care lasts - and can be
restored much easier than poly ever could when damaged. What I wanted to
know was if I could put varnish over wood that has been previously
poly'd, or would it have adhesion or other issues down the road.
Thanks,
Red