checked/split garboard

[Abby]

Our recently aquired 34' ketch (1 1/2 inch carvel planked Honduras mahogany on white oak, copper fastened, built in 1980's) has a long check in the port garboard. The check follows the grain and runs for much of the length of the plank. We found out from the previous owners' notes that at some point, a leak was discovered near the stern, and was determined to be the garboard. First they applied underwater epoxy to part of the check, and then eventually had the boat hauled whereupon the yard rammed a bunch of cotton and seam compound into about a foot of the check. We do not know if the check had opened up wider at that point,(about 6 years ago) but now it is gaping open about 1/4 inch, over a length of about 12 to 14 inches. The area is not leaking now, but as we have the boat on the hard we would like to try and fix the problem. We can't see the plank from the inside of the boat, so we don't know if the split goes all the way through the plank all along its length.

Other than replacing the entire plank, we are considering one or all of the following: 1. pulling out the hardened cotton, 2. splining the open part of the split, 3. adding additional fasteners on either side of the open split, 4. slathering on more flexible seam compound to fill the gap, 5. leaving it as is.

Anyone have experience with this sort of situation?

thanks very much.

[TimothyB]

Well....

Epoxy will be too firm and will help widen the check.

Since she is a garboard, and you don't want to replace the whole plank, I'd say you have a couple O' options:

1) Slather rubbery goop of choice over a reefed and recaulked check. Paint Epoxy OVER the plank just as a moisture barrier.. enough to slow the uptake. If you don't like epoxy, then put several coats of real marine paint down there along with bottom paint before she sees water.
2) Grave it out the full length of the check and glue in a cedar spline (or other softwood)
3) Since it is a garboard, if you don't mind it being visually challenged you could 'cold mold' 1/4" thick plywood over the plank using bronze screws and LIBERAL application of petroleum tar, OR a rubbery sealant of your choice. Sort of like a reverse batten seam.

Hope those ideas help. Personally, if I just wanted a 'for this season' repair, I would just get a white pine plank sawn and replace it. Cheap and no guesswork about behavior.

--T

EDIT: I would also like to say, that the white pine garboard plank in question should be quartersawn, and from clear stock! Hopefully you can even get a good ring count.

[ 05-27-2004, 09:06 AM: Message edited by: TimothyB ]

[Alan Jones]

Hi Abby,

Think Tim has it pretty well sussed, Few things to remember are that the first plank to give problems when sailing hard is usually one of the garboards. The yard probably made the situation worse as the plank will have had a shake in it and the caulking will have forced it open. Yes it will take up but due to the strains put on the garboard when sailing hard the split will be opening and closing, once dried out it will continue to open more and more as time goes by.

The only proper solution is to replace the plank.

[Noah]

I suppose one possible option would be to route out the length of the split about half the thickness of the plank. You could then glue in a "Dutchman" that filled the void left in the plank. It's not going to give you full strength, but it probably wouldn't be too bad.

You would want the plank to be fully swelled before you glue in the new piece though.

The real question is why did the garboard split? Was is just from drying out and being fastened on either edge, or was it because it's being subjected to too much force? How are the floors? How about the fasteners holding the floors to the keel? You would hope that the garboard isn't doing the work of a floor... :eek:

Noah

[RGM]

Noah gets the Gold Star! Everyone else had good input too. However, too often the temptation is to treat the symptom not the problem. Since your sailboat is 34 feet long, your garboards aren't very long. To treat the problem you need to replace the garboard and give everything revealed by the removal the heavy eyeball. Look for an internal cause or failure. Yes, this could be the "tip of the iceberg", "can of worms" type scenario but you really owe it to yourself (and everyone else involved in the boat) to investigate this. You won't regret doing it. Good luck.

[ 05-27-2004, 11:47 AM: Message edited by: RGM ]

[Abby]

Thanks, everyone.

We have not ruled out replacing the plank, although I am loath to rip it off the boat if it's not necessary in preserving the integrity of the hull. The boat is fastened with ring nails, which don't sound like much fun to remove, either. The boat is very sturdily built, the wood is all in fine shape and from what we have seen so far, the floors all look great.
The split or check runs a good length of the plank (in a couple of places it stops then starts again), and is just a hairline following the grain until the 14 inch section where it has had a bunch of caulk shoved in it.
I wish that I had more information on the history but I have recounted all the previous owner wished to tell us.

We definately want to get to the bottom of the problem, if there is a problem, but what if the problem was the plank was checked when the boat was built-- is that alone reason now to replace it? We are still in discovery mode, and are not going to make any rash decisions either way.

thanks again.

[Alan Jones]

Abby, I dont think you have a choice, it would appear that the plank was flawed from day 1, you can see that things have just got worse as time has passed and anything you do apart from replacing the plank is only temporary. Should the split have caused the plank to move then the fastenings will be loose and so on, sorry but in my humble you must solve this problem once and for all. As regards the ring nails cut the plank free, grind the nail off, punch remaiming piece into frame and new nail, different place.

[Abby]

Everyone will be greatly relieved to hear that we have decided to replace our garboard. It wasn't really a matter of if, it was more a matter of when, and while the boat is out of the water now just makes the most sense. We will all sleep better after it's done, anyways.

Since we are new at this, we'd like to hear words of wisdom from anyone who has replaced a garboard, especially on how to clamp or block the plank in place while fitting.

thanks...