Gul repair problem

[Rupert]

Just picked up a Gul from the club to try and make it safe for the owner.

Most of the work is easy. However one bit has me a little stumped. Picture the boat sat bow up, with some water in the stern tank. Now put her bow down. The water vanishes from the stern tank, but not into the cockpit... there are a couple of bung holes in the bottom of the boat, and you can actually see the water draining out of them from between the hull and the glassed in plywood stringers. The water is trapped between the layers, but will drain out into the back tank again when you tip her bow up again.

The back tank has a large block of foam bonded in, so it may be impossible to seal the inside of the tank. All I can think of is to cut/grind a 1/2 inch wide strip of the inner glass off, dry it out as best as it will, then seal it back up so the tank and inside are no longer connected. Any better ideas, please? Taking the whole of the glass and stringers out and starting again, which would be the only truly long term solution, is not an option - my time and the owner's funds are very limited!

[JimC]

I don't know if I'm being dumb, probably, but I can't figure this at all. This is, what, a glass fibre Gull? There have been a lot of interior mouldings on these over the years.
Is there an inner and outer deck mould with a gap inbetween? If so does it really matter if water can get in there as long as it drains when the boat is stored bow up with the stern bungs open? I'm struggling with this!

[PeterV]

I think your proposal is what I would do, a little destruction then not a lot of remedial work and it's done.

[Rupert]

Jim,

there isn't supposed to be an inner moulding - the outside hull and the glass used over the stringers have parted company, and I can only assume that the aft tank has also come away, but as the glass which went over the stringers also went over the lip of the tank, the water runs from the tank to inbetween the layers and back into the tank. Judging by the amount of water trapped in the layup, any plywood once under there is now simply mush.

Having bailed the tank out out just now, I'm wondering whether bonding (somehow) from the inside is going to be the solution, as this wull stick the tank down again. Need a vey thin arm with an extra joint, though...

[JimC]

Judging by the amount of water trapped in the layup, any plywood once under there is now simply mush.

Good grief, sounds like a nightmare... Got to ask if its worth it? Speaking as the master of getting sucked into major rebuilds that have no rational justification this sounds as if it could be another, if I understand the situation properly.
What would be the problem with just leaving it as is until final dissolution? If you were to consider the tank and the stringer void as being a single entity, will significant amounts of water enter there when you have done the other work? If not, well, what are you going to achieve by isolating tank and void other than ensuring there is no exit for water in the void?

[trebor]

Rupert,
if their is a cavity between hull and overlay inside, could you not carefully drill a series of holes through floor layer like a cullender,(use a depth stop on drill bit), allow cavity to dry, paint gel coat over allowing to seep through holes and re-bond the two layers

[chris]

How about one of the expanding polyurethane glues injected in to a few places.
1, it will expand to fill quite big gaps and also travel along smaller gaps.
2, it likes a bit of damp to cure. Ok if it traps wet into rotten timber it certainly wont be a long term cure.

[Rupert]

Thinking on this overnight, I think Jim makes a very valid point. I think I shall add a back bung and then concentrate on finding the leaks into the floor, starting with the bungs in the bottom of the boat. Thank you all for your advice!