On Tue, 04 Apr 2006 14:20:45 +0000, Roger Long wrote:

So is it silly to use marine varnish? It sounds like a good exterior
varnish from the hardware store would do just as well and half the
price.

I've used the super durable, very fast drying, polyurethane varnish left
over from re-doing our hardwood floors for a number of non-boat
projects. It's great. I put six coats on a mahogany base for a model in
one day and it looks like I spend weeks on it. The marine varnish I've
been using takes 24 hours before I can sand it easily and put another
coat on and doesn't look any better.

The problem with PU varnish is that it will still crack and peel like
anything else. But when you need to patch or redo it, what's left is next
to impossible to remove. It's probably the best thing for interiors
though.

If I was sure about the UV aspect, I'd use that floor varnish on my
(already varnished) exterior teak. It sure would be nice to have it dry
in an hour and be working on another coat instead of worrying about
whether the guy next to me was going to be sanding his white paint.

Just how important is the UV, Interior/Exterior business anyway? The
marine varnish I put on some of my exterior trim pretty much disappeared
over the season anyway.

It's everything! UV actually causes the wood to break down, which is what
causes varnish to crack and peel. Think about it -- debonding from the
wood has to happen from the wood side, not the weather side.

FWIW, Cetol has that orange tone because it contains iron oxide for UV
protection. This gives the most bang for the buck in terms of UV
protection. Clear UV protectants are expensive, and not quite as
effective.

I've had great luck with Deks Olje. The #1, basically an oil finish,
builds up quicker and easier than anything. If you like a satin finish
it's good as-is. If you want gloss you can put the #2 on over it. The #2
isn't as hard and glossy as the hardest and glossiest finishes, but it's
good enough for most people. If you want the boat to shine for a special
event, you can just sand in a coat of #1, then slap on a coat of #2. The
best thing about Deks Olje is that it's so easy to maintain, so you'll
actually do it.

I've been using a little Cetol lately, to see how it holds up and how easy
it is to maintain, compared to the Deks Olje. Ask me about it at the end
of this summer.

Matt O.