Taiwan Trawlers hull to deck joints

There is a lot being asked and said about teak decks, window and substructure leaks, but I don't recall seeing much discussion about the hull to deck seal. Is this not an issue based on how they are constructed? And, how are they constructed? I am obsessing about house leaks and substructure delaminations in my search for a new boat and I need something to take off my list of worries!

Thanks all,
John B.

John, We have been dealing with these leaks since we bought the boat. We have about 90% of them under control but there are still a few, especially here in the rain forests of south Florida. Some were resolved by caulking around the hull and cap rail. Others, by injecting epoxy under the cap rail. A few are still leaking. Look first at the stanchion based and get them sealed. Chuck

No hull-to-deck leaks on my Nova Sundeck. Can't say the same about the windshields though. Tried resetting all the panes to no avail. I have used Flex-Seal on my center pane and after eight months we are still waiting for rain to see if it works.

John-- I would say you are correct in saying it's an issue with how the boat is constructed. Grand Banks--- which is not a "Taiwan Trawler"--- fits the deck molding inside the hull in such a way that the deck mold overlaps the hull mold at the top of the gunwale. This is then covered by the teak caprail.

While there is frequent discussion on the Grand Banks owners forum about dealing with teak decks and their seams, screws, and plugs and keeping them watertight I don't recall ever seeing anyone talking about leak problems with the deck to hull joint of the fiberglass boats.

And I notice that even on the newest Grand Banks models, while the teak decking is now glued down instead of screwed and the handrails and grab rails are stainless steel instead of teak and there is almost no teak trim on the boats at all, they still use that heavy teak caprail. So I assume they still use the deck to hull joint method they have been using since 1973.

The deck join depends on method of attachment.
Manufacturers use a variety of these.
The hull-to-deck is one of the more critical, and often one of the weakest joints involved in the construction of a fiberglass boat.
It is the unifying structure that ties the other three sides of the hull together.

Look for loose rub rails or ones starting to fall off. A prime indicator that there is a problem with this joint.

SD

The Eagle build by the CHB yard, decks are fiberglass over ply and the fiberglass is molded to the hull. However, then they added the teak deck, gunnels, hand rails, windless, store box so hundreds of holes where drilled into the once solid fiberglass covered deck. The roof is the same construction as the fiberglass rolls over and down the sides. However again they added add teak trim, hand rails, storage boxes, mast/stays, and dinky davit. So far non of the leaks have been from the deck to the hull joint. The leaks have been from the drilled holes.


However, around/under the gunnels, rub rail windows, hand rails, boxs etc are sealed with caulking which I have replaced as the old caulking was hard and failing. I use 3M 5200 which holds up well. However most other brand of boats also have cauling around seams/joints?

Not on my 77 Marine Trader. No seal and as long as long as you maintain the rail cap seal you are good. Don't and your deck will rot from inside the gunell wall.

Here's the KK42 deck/hull/cap rail detail as designed. We were fortunate to get a copy of the design drawings from another KK owner.

Larry M said:

Here's the KK42 deck/hull/cap rail detail as designed. We were fortunate to get a copy of the design drawings from another KK owner.

Click to expand...

The Eagle deck joint is the same as shown. The deck fiber glass goes up about 6 inches up the hull. Also the deck support beams are fiber glassed to the hull as shown.