foam?

[Jim Kloss]

I've located a persistent leak at the aft edge of the daggerboard trunk. I have limited access to it through a hatch I added in the galley area but there's not enough room to do a fiberglass repair. Just stuffing a towel in the space slows the leak considerably.

Thinking about filling the area with foam. I have some 2-part flotation foam but it expands very aggressively, and I'd have trouble getting it into position. I could use the aerosol insulating foams available everywhere but I'm not sure of its water resistance and the label says "not for structural marine use." I don't think I'd consider this "structural", but .....

Anybody have experience to share?


Jim Kloss
s/v Ambivalence
S2 7.9 #8

[Jim Kloss]

FYI - didn't work

[Jeffrey]

Hi Jim, I think you will have to cut out a portion of the floor...there maybe lead weight in the area as well. Good luck...Jeff

[Sam Buschell III]

Maybe you can pull the lift keel and stop the leak from inside the trunk.

[FEVER]

Before this thread moves away from 'foam', let me add a comment. I would suggest that any foam introduced into your boat be
of the "closed cell" type to prevent it becoming water logged.

[Jim Kloss]

Unfortunately, Jeff was right. Cutaway revealed lead ballast with no access to dagger board trunk. Not sure what I'll do next.

Jim Kloss
s/v Ambivalence
S2 7.9 #8

[Jeffrey]

I have never seen a picture of what it looks like under the floor, but if you cut a way enough floor, can you also cut out the weight, do the repair and replace it all again? Jeff

[Jim Kloss]

I'll post a photo if anyone can tell me how to do it; I seem to recall that there's a trick to it.

Jim

[FEVER]

Jim's comment about the internal ballast adjacent to his leak got me thinking:

Is there any chance that the weight and it's location relative the board trunk and/or
the position of trailer bunks has, or can cause a leak to develop as a boat is pulled over
rough roads at highway speeds? I recall that some much smaller and lighter one design
boats either hang the boats by their guntles or support the entire hull on the trailer.
The San Juan 21s that are pulled long distances seem to leak at the front end of their
swing keel trunk, also.

[Pete]

My suspicion is that S2, given it's reputation for over building, likely laid up a very large amount of fiberglass around the base of the trunk. I think if I were doing this I'd pull the board, clean up the inside of the trunk and look for any weeping. I'd also be very tempted to remove some of the layup looking for a crack or a fault. I bet you could remove 1/4" of material and lay in some new glass.
This assumes you've absolutely eliminated any other possible source.

[cklamp]

Jim's comment about the internal ballast adjacent to his leak got me thinking:

Is there any chance that the weight and it's location relative the board trunk and/or
the position of trailer bunks has, or can cause a leak to develop as a boat is pulled over
rough roads at highway speeds? I recall that some much smaller and lighter one design
boats either hang the boats by their guntles or support the entire hull on the trailer.
The San Juan 21s that are pulled long distances seem to leak at the front end of their
swing keel trunk, also.

New to 7.9's, but have been racing SJ21's for almost 15 ish years now... IME The leaking on an SJ21 in that area is usually due to the swing keel pivot wearing or the owner not using an appropriate set of gaskets against the pivot bolt. I haven't seen any leaks in that area due to structural issues.

Later
C