Advice on fixing garboard leaks

[joliette]

Joliette goes like a train to windward but suffers from garboard leaks! The mast step, steel floors and fastenings all appear to be sound, so I intend to re-caulk the garboard seam along the keel rabbet line as this is where I've detected leaks when she's settling on a mooring after a passage to windward. My thoughts are to rake out the old caulking and then re-caulk with cotton followed by sikaflex (rather than red lead putty). In addition I was wondering if it would help to insert silicon bronze screws through the bottom of the garboard and into the keel between frames, thus helping to further compress the garboard against the keel along the rabbet line? Also, the inside of the bilge is coated with pitch and I was wondering if renewing this would help further? Any advice on this subject would be much appreciated. Thanks

 

[ccscott49]

Trad boats do a black cualking material, you mix with cement powder, lots of people swesar by this stuff, might be just the stuff you need. Not sure about the bronze screws, havent seen a garboard held this way before, but thats not to say it wouldnt help. But I'd be worried sabout it splitting the bottom edge of the garboard, depends what the angle of the garboard to the keel is of course.

 

[Eastermaid]

Had the same problem when I first bought Ceilidh mhor found leak down one side only. Recaulked cotton and red lead cured it for 2 years this year after very hard sail in round the island race now leaks even more than ever so will be doing the same this winter. Thats wooden boats for ya

 

[Peterduck]

I think that a fundamental question is where along the garboard is the leak? I had a similar leak in a garboard seam which had been over-caulked. I jacked up the keel after raking out the seam before adding extra bronze 2" x 12g screws into the keel. This was forward of the heel of the sternpost. If your leak is anywhere near the mast-step, it may pay to install a longer step so that the load is spread over a greater length of keel. Any leak in this area would call for bracing between the butt of the mast and the sheer clamp to try to take some of the load of the mast from the keel to the sheer.
Peter.

 

[joliette]

Thank you all for the excellent advice. The leak is mainly along the portside, adjacent and abaft of the mast step. I will try to re-caulk the garboard first and if that doesn't work I'll consider more major work i.e. some additional wooden floors with "wings" up to the chain plates. However, new floors would really need to be fastened through the keel, which would mean removing the ballast keel to get new bolts in ... unless I just drill right though the lot - floors, keel and ballast (lead) - and insert some new long bolts to tie everything together? I guess that would work, with a BIG drill!

The mast step looks quite substantial to me and I'd like to think that Robert Clark got this (fundemental design stuff?) right by 1950, but who knows! Also, the original wooden mast was replaced with an aluminium one about 20 years ago, so this should've at least reduced the static weight on the keel, which ought to help?

I will try a re-caulk for starters and let you know if it works! Thank again. Mike

 

[Blueboatman]

Any or all of what you have suggested may help.as definitely would a more substantial mast foot,as Peterduck says....and in your mind you are thinking along the right lines when you contemplate triangulating the loads between step,partners and chainplates and 'feathering' that load into the rest of the hulls structure.
I have seen tierods used between the mast step and the lower end of (internal) chainplates,solid bulkheads that do the same,steel ring frames and laminated wood ones.....
Perhaps you can acquire a set of Clarks plans to determine exactly how the boat was put together first? I would think that there will already be screws along the garboard into the keel rebate and it might be worth drawing one and verifying whatever holds the steel floors to the frames/planking too ....
It is a shame to have a boat that can go like a train to windward but be unable to drive it hard . Good luck,perhaps post a piccy or two?