Replacing water-logged bench seats

[wayne kevin]

I have a daysailer that has a number in the hundreds--not sure exactly where, perhaps 150 or so. I race. Recently I weighed my boat and noticed it's gained thirty pounds since a year ago. I have custom seats, which are made of balsa (and chipped) and which extend forward under the cutty to about three feet from the bow--virtually twice as long as other seats I've seen. I'm contemplating replacing the balsa bench seats with pvc foam and glass. Friends suggest that I make life easier and just cut the forward parts of my seats off, but I suspect this might alter the stiffness of the hull and thus am not inclined to do so. First, what are the rules regarding replacing the balsa benches with foam and glass replicates?
Second, has anyone done this and would care to offer advice. Much appreciated....

Wayne

[GreenLake]

Let me understand the construction of what you have. I assume, when you write balsa, that the balsa acts like a core, so you have some glass cover (skin) over them.

I also think I understand that early DS have no molded flotation tanks, so there's no other part of the boat that could have collected the water.

In terms of collecting water, cutting off part of the seats wouldn't seem to fix anything. The part of the seats under the cuddy would be the least exposed to the elements (except when you capsize your boat). Cutting that part off might reduce some overall weight, but if water really is inside your seats, then the wood will continue to hold it and continue to rot.

Whether the seats act as stiffeners depends on how they are mounted. Those of us with "younger" DSs, even if only by a few years, can't really visualize how those seats were originally placed and yours are a custom modification. Is there any way you can post a picture?

[algonquin]

Wayne - Is your boat an actual DaySailer like the ones on this site ?

It appears that it may be a different boat brand or it has been modified by a previous owner or two. Are you sure about the balsa ? Most of the early DS boats had mohogany or similar. Balsa doesn't seem practical. Brad

[wayne kevin]

Thanks guys. It's a 1959 model--and yes, it's a Daysailer I. No camera available, but the seats are bench seats that are 1'X1' and 12' long, extending from the stern to under the cuddy, where they taper against the bulkhead and stop short of the bow. They are balsa core with resin over them--I'm assuming the old seat-wood was replaced, but am not sure. Anyway, I'm leaning towards replacing them with a Diviny foam core structure. I'm wondering if anyone else has done this? At any rate, thanks for the help.
W

[kokko]

I'm don't knwo what to suggest as a replacement, but I have seen one of these old boat and there were a pair of metal tanks under the gunwales for positive flotation. As i recall, there were about three feet long and 4-6" diameter cyclinders.

Whatever you decide to do, incorporate some positive flotation in the bench replacement.

[GreenLake]

.. the seats are bench seats that are 1'X1' and 12' long, extending from the stern to under the cuddy, where they taper against the bulkhead and stop short of the bow. They are balsa core with resin over them--I'm assuming the old seat-wood was replaced, but am not sure. Anyway, I'm leaning towards replacing them with a Diviny foam core structure.

The number of old DSs with wooden benches are probably a rather small percentage of the total boats out there, and those with additional modifications even smaller...

If you don't have a camera, can you describe how the seats are fitted to the hull?

Kokko is right, you do want to add flotation - the more the better, actually. Chances are, whatever you have now, if anything, is minimal.

I've looked up Divinicell, and it appears you can get with densities that match balsa, but some grades are 70% heavier. (but still lighter than waterlogged balsa )

Other than getting the weight and strength right of your foam, I don't see why cutting out a matching form and glassing it should present unsurmountable problems.

[wayne kevin]

GL.
Thanks for your advice. The bench seats are glassed against the interior bottom and sides of the boat--just like other daysailers, except, as I said, they extend under the cuddy about two feet further, where they taper with the narrowing of the bow and stop. But they are glassed. Your comment on Divinicell (sp?) is interesting; most everyone who's "weighed in" think it would be lighter. Can you imagine going to all this trouble and having the boat be heavier?!! Maybe I should look into balsa replacements--though this will ultimately lead to the same problem. The plan so far, at any rate, is to carefully removed the entire bench seat with a small roto-blade saw, then use it to build a plywood mold, make a Divinycell replicate around the mold, then glass it back to the same position. Maybe I'll just go on a diet....

[Bob Damon]

Please check Bylaw 3, paragraph 5.5 which says that the original (wooden) seats may be replaced with wood or fiberglass provided the original seating areas and dimensions are maintained. Having your current seats outside of the original dimensions are not class legal per this specification. If you are replacing what you have, you are limited to wood or fiberglass. Let me know of any questions. Thanks, Bob Damon

[wayne kevin]

Thanks Bob. I'm confused. When you say fiberglass, doesn't that include core material? And how do I know what was original with regard to this old boat? Are there pictures? It's been certified in the past, and I certainly don't want to do anything that would run afoul of the rules--I just want to stop the water-logging.

[swiftsail]

Bob,
Are you saying if I build new seats and extend them a foot or two forward, that would be illegal?

Steve

[Bob Damon]

I have two questions so will try to answer the best I can:

For Wayne, The intention is to keep the boat as it was designed, eventhough there have been additional designs afterward. If there is a core material wrapped in fiberglass my ruling is that would be ok. If it is wrapped in carbon fiber, that would not be legal. To determine what the original seats looked like, I would recommend checking other three digit boats. Dave Keran is a good resource as he resurrected Vieja. It also is not uncommon for a boat to get measured in as not every bylaw is listed in measurement. See my reply to Steve below about shape and extending the seats.

For Steve: The bylaw says original seating area and dimensions. That being said, folks with 4 digit boats with the seat tank seating often add wood extensions forward to allow crew to move weight forward. I would say that if you replaced the seats in their original configuration, then added a separate add on that extended the seats forward that would be ok but not as one continuous piece. I know this sounds trivial but that is how with rules work.

For other questions, please send me an email for detail nomadbob@aol.com. Thanks!!

[swiftsail]

Bob, YES that is trivial. If we can extend our seats forward, why can't we just build them that way from scratch! So to make my seats legal I need to cut them, put a couple layers of tape on them and then they will be legal!

[wayne kevin]

Thanks Bob. This is getting interesting; I think I'll listen for a while and try and figure out what to do.
Wayne

[GreenLake]

Wayne, some foams come in different densities, even though the generic name is the same. Divinycell (y/i?) covers a range from 60 to 250kg per cubic meter, so that's a range of 4 in weight. Balsa also covers a range, but I'd assume that for this purpose one might go for 160 kg per cubic meter (just a wild guess).

You may not need the heaviest foam, but in general, Balsa is pretty tough to beat. If your seats had balsa running lenghtwise, that would have added strength, but of course it's the wrong thing to do from the point of view of minimizing waterlogging.

About your configuration. You only state that the seats are longer than what you have seen, but is that definitely due to a modification by a previous owner? There've been a number of design tweaks in the early years, and some people have boats with rather unique combinations of features, like the one poster who has tank-style seats that never were filled with foam flotation.

[wayne kevin]

GL--I've been able to trace ownership back a ways (30 years or so)and everyone remembers the old boat just the way it is--with the longer bench-style seats. Your comments about balsa being stronger has got me wondering if perhaps I should redo them in balsa, while making sure to seal them well with resin. The current ones have chips (which reveal soggy wood) here and there, but maybe restoring the original is the way to go. At any rate, I really appreciate your commentary--thanks again.