The original sealant
for the hull
joint was a Polysuflde caulk like 3M 101 or LifeCaulk. This stuff does not harden or break down and will be a permanent seal if done right in the first place. The Dolfinite was just a sealant under the cap rail and isn't the real water
proof seal. Replacing the Dolphinite under the caprail with something else probably isn't going to be a long term fix if it is a problem with the actual hull
joint seal rather than the fasteners.
First you need to figure out where the leaks
are actually coming from. Is it the fasteners for the caprail or the hull to deck joint that are leaking?? If it's the fasteners, removing them and carefully resealing with Polysulfide, Polyurethane
, or Butyl caulk will solve the problem. If the leaks have been getting worse with age, it's quite possibly the Dolphinite drying out and letting water
in from around the fasteners. When you put the cap rail back down, be sure there is caulk around every fastener as it goes into the glass. Screw the cap rail down dry, remove it, run the cap rail fasteners in with the wood off, apply sealant around the fasteners, caulk under the rail and then screw it back down. Also, lightly counter sink each fastener puka so there is a caulk donut where the fasteners enter the glass.
If the water is coming from the actual hull to deck joint, things are a lot more complicated. It may just be a small area where the workers missed with the caulk. On my boat, had one area in the head
that leaked. As far as I could tell it was from the hull to deck joint, not the fasteners though I was never absolutely sure. The leak was pretty manini and just stored stuff in that small area in water proof containers. If it is leaks over a large area because of improperly caulked hull to deck joint, the only real fix with the existing architecture is to separate the deck from the hull remove all the old caulk and reseal with your caulk of choice. I like polysulfide, have pulled up pieces that I caulked 30 years ago and the LifeCaulk was still pliable and adhered to the pieces as the day I put it down. 5200 will definitely hold the hull and deck together. Some people swear by it, others swear at it. 4200 isn't as adhesive
but you shouldn't really care as this is a task that shouldn't ever have to be repeated. Butyl is another option.
Can't remember whether Westsail used sheet metal screws, machine screws or a combination of the two for the hull to joint. If they did use sheet metal screws, replacing them with machine screws, nuts and washers could solve your problem. Actually, removing all the hull to deck fasteners that are under the caprail and carefully resealing all of them will probably go a long way to solving your leak problems. None of the mass production builders took enough care in caulking the fasteners anywhere on the boats to insure a leak free job.
Another fix that is actually pretty easy to do but takes some skill to get a good finished appearance is to glass the hull to deck joint. Thourougly clean out all the old caulk under the cap rail, clean with Acetone or other nasty solvent. Use gloves and try and do it on a day with a good breeze. Fill all the cracks and crevices with thickened epoxy
resin. Grind the surface flat. Grind a bevel 4" or so down the hull and bulwarks several laminates thick at the edge and tapering out as you go down. Don't go crazy with the grinder. Laminate several layers of cloth/matt fabric
(Stitched Fiberglass Fabric - Fabmat
) with epoxy
resin over the joint and down the sides of the bulwarks and hull where you've ground off the glass. Use filler and a foam pad grinder to get a flush finish, paint
and then rebed the cap rail being very careful to seal the fasteners. Have seen this done on a couple of the very early Westsails that had a wood clamp instead of the fiberglass
flange for the hull to deck joint. If you have a very early Westsail with the wood clamp, that clamp rotting out could be the cause of your leak problems. Glassing the hull to deck joint will be about your only fix.
Former owner/builder of kit Westsail #163