weeping keel again

[Ardenfour]

Have taken previous advice and drilled pilot holes through damp patches on keel and was rewarded with spouts of liquid, some clear, some milky. The clear stuff tasted like salt water - I didn't sample the milky stuff! This is coming from low down on the keel, presumably from voids in the concrete encapsulated ballast. None of the fluids were rust stained. There is no way I can get access to the area, short of digging the concrete from inside the boat, or by cutting much larger holes in the keel. Is it possible that water has found it's way between the outer keel and the ballast and that the concrete is breaking down in some way?
Having drilled the holes and drained the water, what's the best way to seal them again? Can't see how thw inner area could be dried out (or the outer surface, which continues to trickle water) enough for epoxy to adhere well. Plug the holes with lifecaulk under pressure?
Help!

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[sailorman]

the Trintella 29 i fitted-out had cast iron keels ????.

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[Ardenfour]

word from the original owner is a ballast comprised of a quantity of lead ingots supplemented by lengths of railway track all encased in concrete

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[cpedw]

A technique I used to rebond a P bracket in a fibreglass hull amy help.
Drill several small holes near the top to connect to the cavity(s). Corresponding holes are needed at the bottom. Wait for natural drainage to stop (you need to make sure there's no fresh contribution getting in anywhere).
Using a syringe, inject acetone into the cavities. It has low viscosity so it penetrates well. It is also strongly hygroscopic so it absorbs water. Its other useful property is it evaporates readily, having hopefully degreased and dried all the places it visited.
On the Health & Safety side, remember acetone is a glue-sniffer's dream and it burns very nicely too. So keep the place well ventilated and free from sparks, flames etc throughout.
After that, inject epoxy into the same spaces. This part surprised me, The epoxy penetrated nearly as well as the acetone, surprising given its viscosity, especially at low temperature (it was winter when I did this job).
Hope it helps.
Derek

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[boatmike]

I think you have identified the problem yourself. Filling GRP hulls with concrete is definitely not a recommended practice. It's usual to embed the ballast in resin which bonds with the keel. Concrete won't of course and its inevitable that any water inside the boat will get between the concrete and the GRP. Can only suggest you open up the areas as much as possible removing all "soggy" GRP and making some deliberate (but temporary!) drain holes in the very bottom of the keel to let gravity do as much as it can for you. Then wash copiously with fresh water to get as much salt out as possible. If you are intending to leave the boat out of the water for the winter I would then tend to leave the ground out areas until the spring and see if things look better then.
To stop the problem re-occuring you might consider glassing over the top of the ballast when you are sure it is dry which will help to stop bilge water getting down there at least. Either way I would be more aggressive in opening it up to cure the problem and not be tempted to try and plug the holes until it is dry. All you have done so far by the sound of it is relieve the pressure in these voids. You won't solve the problem until you open it up over the entire area which is soft...

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[roger]

It might just be possible to drill or dig a hole down through the concrete close to the hull bottom to form a small sump. You could then pump out the sump from time to time. This would also give you some idea of whether complete removal of the concrete is practicable which sounds from what other people say to be the preferred course to take.

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[Ardenfour]

thanks for all the helpful replies. I had toyed with the idea of creating a deep sump for bilge water as on the steel Trintells. Tapping around the keel area highlights some large hollow areas deep down which would serve the purpose. The concrete has been glassed over but I found an area below the engine where the glass had come away and I was able to scoop a sand-like slurry with a screwdriver. I can't see the keel drying out without any air circulation - the only way would be to remove all the crap and the ballast (3850lbs) piece at a time. I suppose I can always glass over the top again if removing it all becomes unfeasible. Good excuse to make a sump anyway. I haven't come across any soggy or delaminated grp. If I sit on the ground and kick the keel a jet of water squirts out the holes I've drilled, so it would seem that the encapsulation has come away from the hull.

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[Mudplugger]

In the dim distant past, I was a very proud owner of a Bradwell 18, which at the time sailed like a witch, and smelled like one of the great unwashed. Eventually the cause of the rancid niff was identified as coming from the bilges which utilised concrete & punchings to support the centre keel, I spent several happy hours with a club hammer & bolster removing the whole noxious mess & several more happier hours replacing with an epoxy/lead shot mix. Have to say that the lead/ epoxy mix weighed a lot more than the previous mixture, so got a better boat as a result. Bearing in mind that Bradwell's were not the strongest of hull's and my belting with a club hammer/chisel had no ill effects, might be the way to go? HTH Tony W.

<hr width=100% size=1>Tony W.

 

[sailorman]

Original were cast iron as I remember when drilling to fix table leg pedestals

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[kds]

Yes - Tylers filled theirs with cast iron according to their plans.
Ken

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