Wet, damp or dry for caulking?

[Wensum]

I've posted on Stan Derelian's thread in FAQ, but it seems to be dying quietly and I need advice.
My 25' carvel hull (1936 gaff Broads cruiser) was taking in some water along the gardboard seams and needs recaulking etc. She's on a cradle in an unheated shed and will be there 4 months, drying out slowly.
My question is this: WHEN should I do the work? Just before re-launching, when most dried out? Should I spray water in the hull to deep it moist/wet? Do it now while the planking is fully taken up? What to do please?

[Bob Cleek]

It depends... which isn't much of an answer, I guess. If I were you, I wouldn't think about caulking until I determined what the problem was that caused the leaking along the garboard seams. You did say "seams" (plural), didn't you? This is almost always symptomatic of a problem with the floor timber fastenings, either floor to keel, or floor to frames. Since the floors hold it all together, when they work loose, it's the garboards that pull away from the keel, creating leaks like you describe.

No amount of caulking will fix garboards leaking due to floor problems. All the caulking will do is stick something in the space which will pull it all apart more when she swells up. Check the floors and only after that caulk.

As for caulking, I would attempt to get it in there before she really dries out, although it will work okay otherwise, so long as you don't pack a seam that is too wide. You have to look at it. If the seam opens 1/8" that's one thing, it it opens 3/8" thats another. Have somebody who knows what they are doing look at it for you and suggest just how much to pack in there. Sometimes the best way to go is to pack the seams with "Slick seam" or soft soap and launch the boat and let her take up on her own. The soap will wash away and push out as she swells. Then, if the leaks don't stop in a few weeks, you can haul her and caulk wherever there's a problem. If you are lucky, there won't be much and the job may even be done "in the slings" in a few hours.

Do have somebody take a look at your floors and frame ends. Leaky garboards are so often the result of structural problems and packing the seams with caulking only makes them worse. The problem may only be a couple of floors that need replacing or refastening.

[ 11-22-2004, 08:47 PM: Message edited by: Bob Cleek ]

[Mrleft8]

I caulked my boat when it was very dry. These things happen when you take a year to build a boat... I tried to swell the planks with a humidifier, but it clearly wasn't enough. A few days after launching, the seams were spitting caulk. Unsightly, yes, but tight. I only took on about a cup and a half of salt water.
So my advice is.... Damp. If you do it too dry you spit caulk. If it's too wet, you probably won't get a super duper good seal....

[sdowney717]

As for sitting in the slings, many of these yard operators dont want you tying up their lifts. On my first haulout when suggesting this I received an instant rebuff. And every time I was out for longer than a week, if the planks started opening up amd they happened to see this, it was always a negative reponse from them. Frankly IMO, the pressure is on a conventionally built wooden boat owner to get back in the water quickly. And when I went to haul out this last time out of 4 yards, 2 refused to haul wooden boats. They cited lawsuits from owners that buy these boats and dont know what they are getting into repair wise, then when the boats are hauled or put in and they dont like what happens they sue the yard or the wood boat is simply abandoned because the work is too hard. It was getting a little scary there finding a yard willing to haul out.

[Wensum]

Thanks Bob for taking the time to reply so fully. But I'm a bit lost with your "FLOORS" that hold it all together.
The only floors I have are the cabin soles which are loose and when lifted out expose the inside of the hull, the ribs and planking. It looks to me as though the ribs essentially provide both the shape of the hull and its integrity. The fastenings of planks to ribs look OK, but I'll have them checked.
There is some slight seeping (very little) of water from seams for a couple of planks out from the garboards, but it is the latter which cause most problem. And yes, plural.... on both sides of the hull.

[Bob Cleek]

The floor timbers are pieces which span the top of the keel between the frame heels and tie it all together. They are fastened to the frame heels and to the keel. In that way, they hold the frames to the keel and make the boat a unified whole. Sometimes they are made of metal, or, if the frames are laminated, you might seek a whole frame and floor assembly in one, i.e. a "ring frame." In some boats they are hefty and in others somewhat smaller.

What happens is that the stresses on the hull are such that when the frame heels aren't solidly holding, it's always the garboard seams that will start to pull away from the keel and leak. It isn't the lower garboard plank fastenings that keep the topsides attached to the keel, it's the floors.

[Wensum]

Thanks, Bob, I understand perfectly. I went down to the boat this morning and had a good look, transverse wooden members (floors) exactly as you describe.
I'll rake out the seams then get someone more knowledgable than I to check the fastenings to the floors as you suggest. I'm indebted.