In article , Roger Mcmillan
wrote:

I want to fit teak decks to my 37ft aluminum sailboat. Does anyone know
whether I can fasten from below, to save all that tedious plug cutting,
fitting and sanding?

I thought that with aluminum it would be quite strong if I drilled from
underneath - the fasteners should really only be required until the bedding
compound sets.

Any thoughts? Thanks

Don't do it. You're going to take a waterproof deck made of the same
material as the rest of the hull and either glue timber to it or drill
*lots* of holes from underneath.

The first method - glueing - is going to result in differential
expansion of the timber & aluminium. Sooner or later you *will* get
delamination, water ingress and probable poultice corrosion of the
aluminium.

The second method is just so idiotic that it doesn't bear
contemplating. You'll still have movement of the timber vs metal but
now you'll not need to wait till the al deck corrodes thru, you've
provided thousands of holes to let water into the interior. It *will*
leak, it's only a matter of time, and when it does finding the source
of the leak will be damn near impossible, and basically unfixable.

If you want a wooden deck, buy a boat designed for one. The proper way
to do it for a metal hull is a bond beam with waterway around the hull
topsides then a conversion to metal or wooden deck beams, a plywood sub
deck sealed with a waterproof membrane and then a teak covering. It'll
still leak, most likely, and it'll still be problematic WRT corrosion
around the peerimeter where the ply laps the metal waterway strip, but
at least you have a chance of keeping the leaks isolated & under
control.

When shopping for a boat, if I saw one with an abortion like you want
to do, I'd either walk away instantly or discount the price to cover
redoing the deck to designer spec. Keep the resale in mind.

PDW

OK, I get the message. Don't drill holes in the deck! The designer also
muttered something about "all that weight topside". Teak decks do look good
though! Thanks for all the input.
Cheers
Rogermac


"Peter Wiley" wrote in message
. ..
In article , Roger Mcmillan
wrote:

I want to fit teak decks to my 37ft aluminum sailboat. Does anyone know
whether I can fasten from below, to save all that tedious plug cutting,
fitting and sanding?

I thought that with aluminum it would be quite strong if I drilled from
underneath - the fasteners should really only be required until the
bedding
compound sets.

Any thoughts? Thanks

Don't do it. You're going to take a waterproof deck made of the same
material as the rest of the hull and either glue timber to it or drill
*lots* of holes from underneath.

The first method - glueing - is going to result in differential
expansion of the timber & aluminium. Sooner or later you *will* get
delamination, water ingress and probable poultice corrosion of the
aluminium.

The second method is just so idiotic that it doesn't bear
contemplating. You'll still have movement of the timber vs metal but
now you'll not need to wait till the al deck corrodes thru, you've
provided thousands of holes to let water into the interior. It *will*
leak, it's only a matter of time, and when it does finding the source
of the leak will be damn near impossible, and basically unfixable.

If you want a wooden deck, buy a boat designed for one. The proper way
to do it for a metal hull is a bond beam with waterway around the hull
topsides then a conversion to metal or wooden deck beams, a plywood sub
deck sealed with a waterproof membrane and then a teak covering. It'll
still leak, most likely, and it'll still be problematic WRT corrosion
around the peerimeter where the ply laps the metal waterway strip, but
at least you have a chance of keeping the leaks isolated & under
control.

When shopping for a boat, if I saw one with an abortion like you want
to do, I'd either walk away instantly or discount the price to cover
redoing the deck to designer spec. Keep the resale in mind.

PDW