Leak in keel

[Athene V30]

I have a very annoying leak that I have spent the last 4 seasons trying to fix and still have'nt!

Boat is '72 vintage, GRP and keel is hollow forming part of the hull rather than being bolted on. I think that the leak is from a fine crack at the turn of the hull into the keel at the aft end.

Winter 05/06 had hull sand blasted, filled, faired etc and 5 coats of primer. Winter 06/07 filled crack and primed 3 or 4 coats but still it comes in. Probably get 1 gallon in 2 or 3 hours which float switch bilge pump coapes will perfectly adequately. Trouble I think is that when boat is ahore the weight of the boat is keeping the crack closed but when the boat is lifted the weight will 'open' minutely making the filler ineffective.

Have checked it is not water from fresh tank, from engine space etc. It happens regardless if it has rained or not.

Next idea is to beach next weekend and to rub back the area I think is the leak and to paint with epoxy resin on outside then reantifoul on top. However do not know if this is flexible enough or not. On the inside was considering using "crack cure" (a small white plastic bottle) and then coat with epoxy on inside too. Is this a good idea or a waste of time? Any other suggestions (other than buy a new boat!)

 

[DanTribe]

Have you checked the P bracket mounting? [assuming you have one]
I spent much time changing stern gland packing etc., only to eventually find a minute crack in the GRP over the P bracket. Worth a look at least
Captn Tolley's Creeping Crack Cure is marvellous stuff, but I think mending keel leaks is asking too much.

 

[Athene V30]

Thanks for the suggestion but no P bracket.

Not tried the creeping crack cure before but hoped might help in combination with epoxy on outside! Suppose it cannot make it worse! Not sure how quickly epoxy dries - will I be able to get on a few coats and then antifoul between tides? Forecast for Sat is dry and 16 degrees C.

 

[aitchw]

If you have a crack that opens enough to let water in then there has to be a serious weakening of the structure and that would worry me far more than the water itself. It wil also be allowing water into the glass matting which is also bad news.

Can you access the inside of the hull where the crack is?

Creeping crack sealer will do no good if the fracture is opening when in the water and it has no strength in itself so will not be helping from that point of view. Just plastering epoxy over it won't help much either without layers of glass to give it strength.

You need to clearly establish the extent of the crack and reinforce the hull from the inside before grinding out and refairing the outside. Just filling the crack even with epoxy will not solve the problem permanently.

 

[Clyde_Wanderer]

Agree with Aitchw.
It sounds like a fracture in the deadrise area of the hill at keel.
The fact that after all the repairing you have done hasent cured the problem is itself evidence of a deeper underlying split, crack, fracture whatever you want to call it.
As adviced you should get her lifted out, supported with keel off the ground, and if you cant find the crack from out side, then you may have to fill the area inside with water and see where it exits.
Dont for get two things, 1, this crack wont always have been there, and definatly wont get smaller, 2, its right through the laminate if its letting water in, and remember its this laminate that is holding your keel in place.
Find the crack ( every last mil of it ) grind it out along with a large area around it, far enough in to almost penetrate through, and repair with epoxy resin and cloth lamination, and I would be considering about 6-8" either side of the crack to get a secure repair.
Then build it out with this laminate and fair off, then seal with epoxy, either paste or resin.
A day or two's work could save you a lot of hastle later on, even a lost keel.
Sorry for sounding so morbid, but one must always consider the worst possible scenario when considering a repair like this.

 

[MikeBz]

A gallon every couple of hours is a fairly substantial leak. If the crack is being opened sufficiently by the weight of the keel hanging on the hull (in water) then it would be opened rather more by the weight of the keel hanging on the hull when out of the water. So... if you can accept that it'll cost you some ££, turn off the bilge pump for a few hours and then get Morgans to put haul the boat out with their sling hoist machine, dry off the offending area and see if/where the water weeps out. Just a thought (though not a particularly cheap one).

Mike