Leaking clinker boats

[tidclacy]

I note lots of questions and discussions about leaking clinker boats and the use of sealants. Is there not a case for trying to tighten the fastenings first? If one did do this would it be before putting her in the water or after? I have used Slick Seam in the past which is easy to apply and seems to work well, has anyone else used this product?

 

[Woodlouse]

A clinker boat should tighten up herself once launched. If she persists then she may need refastening.

 

[Keith 66]

The problem is many people insist on keeping a clinker boat ashore for extended periods of time & then wonder why it leaks when they launch it. Different planking timbers will react differently, a mahogany planked boat will take longer to swell up whereas a larch or spruce planked one will take up in half the time. Also dont forget that if you refasten an old boat that is bone dry, when the wood swells the wood will crush to an extent so after several cycles you will be back to square one.
I restored & owned a spruce planked 1938 Rye beach boat, she had been out of the water for years, the sawn oak floors had shrunk & i had to wait weeks before sailing her lest something break. Once everything had swelled up she was fine & had dust in the bilges.
She has never been refastened and is now 70 years old.
If i had refastened her at the begining the heads of the nails would have ripped through the planking as everything swelled.
On an old boat that has had oil or tar on it you are wasting your time with modern sealants, by all means use a non setting one like evomastic as it wont cause any damage as it squeezes out
On a newer one it may be ok to use a bead of sikaflex along the outside of the land if its dry sailed.
Or get a glued clinker or simulated GRP one!

 

[Seanick]

The problem is many people insist on keeping a clinker boat ashore for extended periods of time & then wonder why it leaks when they launch it. Different planking timbers will react differently, a mahogany planked boat will take longer to swell up whereas a larch or spruce planked one will take up in half the time. Also dont forget that if you refasten an old boat that is bone dry, when the wood swells the wood will crush to an extent so after several cycles you will be back to square one.
I restored & owned a spruce planked 1938 Rye beach boat, she had been out of the water for years, the sawn oak floors had shrunk & i had to wait weeks before sailing her lest something break. Once everything had swelled up she was fine & had dust in the bilges.
She has never been refastened and is now 70 years old.
If i had refastened her at the begining the heads of the nails would have ripped through the planking as everything swelled.
On an old boat that has had oil or tar on it you are wasting your time with modern sealants, by all means use a non setting one like evomastic as it wont cause any damage as it squeezes out
On a newer one it may be ok to use a bead of sikaflex along the outside of the land if its dry sailed.
Or get a glued clinker or simulated GRP one!

Agree with all of the above!!

 

[cliffordpope]

I tarred the bottom of mine and put her back in the water last year after 25 years ashore. Apart from a few stupid places, eg from a rivit hole I had forgotten to redo, the only sigificant leak was from inside the prop shaft log, which I successfully plugged pending attention next haul-out.
She leaked at about the rate of a 20 second burst on a small Rule pump every half an hour, but slowed right down after a few days. I think the normal rate now is about one short burst a day, and even that may be partly rainwater.

Most of the lower planking is original 1880, probably larch, with new garboards known to have been fitted in 1926.
The hull was reported to have been soaked annually in hot tar and creosote since new, which doubtless makes it pretty impervious to water.

 

[mikefleetwood]

OK, following on from these posts -

What is the "best" traditional-style treatment for below the waterline?

I have a clinker-built ex-fishing boat (possibly ex-Navy before that, but no hard information). Intended use is to be kept pulled up the beach (ie dry) then pushed into the sea when needed. This is the normal mode of operation for Cornish cove fishing boats. What would/should the timber be (have been) coated/soaked with to prevent leaks each time it is used, until it "takes up"?

This is a long-term rescue/restoration project.

 

[Keith 66]

My Rye beach boatt was apparently soaked in linseed oil & turpentine when built & was tarred, the linseed oil treatment was repeated regularly throughout her life, when i rebuilt her she was stripped back to the wood & a mix of linseed oil, turpentine & a good splash of stockholm tar was applied. Once it was dry which took weeks i put a coat of black tar varnish over the top, seemed to work fine & smelt great!