Hull / Deck Joint

Author: Chris Bright
Boat: Yindee Plus (43)

We have had the problem of isolated water ingress at the deck join. It was mostly coming from the actual join itself where the mastic had hardened off but also a few screw holes. The leaks were usually fresh (rain) water and got intolerable when we replaced the head linings. We exchanged the old plywood panels covered in foam-backed vinyl for expanded PVC board. The new board is impermeable and suddenly we had small leaks everywhere where once the plywood/foam would soak up the little bit of water coming in. It is not effective to deal with these problems from inside the boat although isolated screw holes could be sealed with Sika from inside. Our solution was to replace the rubbing strake with new Iroko (teak too expensive in NZ).

On deck, we first racked out and sealed the inboard join between the cap rail and the deck moulding with a good bead of Sikaflex. Then we stripped the thin outboard rubbing strake completely and gouged out a good, deep V-shaped channel along the join on the vertical face between cap rail and side strip. This channel we filled with some serious mastic. Finally the new Iroko cap rail was Sikaflexed back in place but I decreased the screw centres to 300mm to make a really solid bond. We made sure we had a complete Sikaflex bond behind this rubbing strake; no gaps.

This has worked fine and we’ve had no water ingress since. When we replaced the head linings we also had the saloon windows out and rebonded them. A couple of our 1989/91 windows certainly needed it – they were way-too easy to get out.