You know, you might want to re-think your choice of materials here. cedar's
pretty soft, and wouldn't look very good very long if left natural and
unfinished, both from the weathering and from the damage to the wood that
occurs in everyday use - from walking on it, to dropping winch handles on
it, to scrubbing away at the mildew to get it looking bright again. Even
vertical-grain teak, as tough and oily as it is, weathers and wears and
erodes away over time. I've got a teak deck that was over an inch thick when
it was built, and there are spots on it that are no more than 5/8" thick
now. Scrubbing the deck to brighten it up erodes the soft grain, and then
you're tempted to sand it to recover the smooth surface, and before long
your three-eights of an inch is gone.

You're not likely to find a finish that you can apply to it that will
protect it the way you want, without losing the (slight) non-skid properties
of an unfinished deck. Varnish it, and it'll be slippery as hell (although
you might find a non-skid additive that would remain reasonably clear - some
people have successfully used tiny glass beads, which leaves a sort of milky
translucence). What did I do with mine? Eventually I gave up and painted it.

A number of years ago a renowned boat builder, Renaissance Yachts, launched
a Herreshoff Bounty replica, 57', exquisitely built, with cedar decks like
you're describing, and I saw it up here in Port Townsend, WA, about a year
after it was built. Even after that short time - a year! - the caulk had
begun to separate from the sides of the seams. We just shook our heads. I've
caulked the teak decks on my 41' sloop several times in the years I've owned
it, and generally I could get the caulk to adhere to the sides of the seams
for around five years before I started having trouble.

However, all that aside, if you can't be dissuaded from using cedar, I'd
suggest Alaskan yellow cedar instead of Port Orford, which is getting
scarcer and scarcer by the year.

My advice? Put another layer of plywood on the subdeck, glass it, and paint
it.

Tom Dacon

"Shanghai" wrote in message
oups.com...
I'm building a 40 ft. ocean cruising ketch. My deck plan is to be
Port Orford Cedar strips, (about 3/8 inch thick, vertical grain),
epoxied onto a fiberglass sheathed epoxy subdeck. How would you treat
the exposed wood to preserve it but maintain it's non-skid? I'm
thinking of stabilization from shrinkage and cracking of the exposed
surface primarily. Rot protection and stain protection are other
considerations. Real world experience is especially desired.