Balsa Core

[minaret]

I would agree with the OP-don't buy boats with balsa. Opinion formed by removing acres of rotten balsa core.

[rognvald]

I find it interesting that the OP is afraid of buying a boat with balsa core. Then, what's the point of this discussion? Buy a solid fiberglass boat. There are perhaps thousands available on the market in his size and price range. Do you really believe the OP is going to change his mind or is this just another troll with 5 posts asking a tired question? CF has countless discussions related to this topic with all the pros and cons. If you're not a troll, BUY A SOLID FIBERGLASS BOAT!

[a64pilot]

Yes, but there is a third option, cores other than Balsa.
Is there really a such thing as a solid glass boat, hull and deck? I would think it might be a little heavy

[Dulcesuenos]

We have a boat with balsa core, the thing many dont think about is construction. None of our large hatches, thru hull, stanchions or deck hardware are near the coring, they are all through areas of solid glass. If you think that a solid glass boat is the answer, they jave their problems too, and can delaminate or have serious osmosis. Foam cores, yeah those can be even worse....ive seen newer foam cores saturated, once they compress they keep compressing etc etc, get a good survey,
Maintenance is key, deck hardware should be rebed periodically no matter what it goes thru

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[clockwork orange]

To adopt the attitude of not buying anything with a balsa core would be to severely limit your options and would be ridiculous as not all balsa boats are rotten (just most of them) Just be very aware and don't buy it if its wet. A lot of people use the moisture meter as a means of driving the price down to account for repairs, I would suggest that you would be better of to pass and continue the search for a dry boat even if it may need sails, electronics, even mechanical work. The most important part is good bones.

Steve.

[skipmac]

Originally Posted by a64pilot

Yes, but there is a third option, cores other than Balsa.
Is there really a such thing as a solid glass boat, hull and deck? I would think it might be a little heavy

There are cores other than balsa but they were not used that often. 30 years or so back some builders started using foam for cores but there were some serious problems with some foam core boats. If I recall when they used the foam core in the hulls over time the flexing pulverized the foam so you ended up with two thin skins of fiberglass with a layer of powder in between. Not good. I think newer grades of foam have addressed that issue.

Off the top of my head I only know of a few boats built of solid glass with no wood core but, contrary to some opinion, they were not that common. I know the CSYs were built with no core and they are heavy. Also the decks, though very strong, without a core are kind of flexible and you get a little trampoline effect in the large, flat areas.

Would be interesting to get a list of boats made without wood cores.

[rognvald]

Originally Posted by a64pilot

Yes, but there is a third option, cores other than Balsa.
Is there really a such thing as a solid glass boat, hull and deck? I would think it might be a little heavy

Ct 56 is a solid glass boat: hull and deck. Heavy . . . you bet! Dry weight: 61,500 pounds.

[a64pilot]

I know IP uses some form of microballons in resin as a core in the deck, I've never heard of a failure, one reason I ended up with an IP, I'm sure it's heavier than Balsa

[capttman]

Originally Posted by Ernest Skublics

Hello, Friends!

I want all your wisdom. I have raised this issue of balsa core a couple of times but never got much of an answer. I have sailed for over 65 years and have never experienced a boat that doesn't get wet -- yes, leaks, particularly from the top. Thus I cannot understand how designers can expect no water to find its way into and in between layers of fiberglass, especially with a spongy balsa core! And once the water gets in, it does not get out! So, brilliant idea to create a light boat (I used balsa as a kid to built model airplanes!), but why would I buy a used -- or even new -- sailboat with balsa in it, unless I wanted to keep it in my living room, God forbid that I should put it in water!

I am now wishing to find a small, easily singlehanded boat for a geriatric skipper (=me), something like a Beneteau First 235, or a Freedom 25 -- even a Nonsuch 22, if I could afford it and it wasn't so slow! But I suspect both the Beneteau and the Freedom are balsa cored.

Could you comment on the balsa issue? I HAVE done my research and read a lot about it -- very little in its defense. Also, do you have any suggestions for my choice of a boat?

I would be extremely grateful for your advice.

Ernest

Most balsa used today and as far back as the 90's was impregniated with resin which helps it resist breaking down. It is also laid on edge as it is cubed and held together with a thin sheet of glass. U would not rush to the conclusion just because you had a leak you have a problem.. Oh some do but most dont


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[Celestialsailor]

Originally Posted by Island Time O25

A boat builder friend of mine once told me not to be too afraid of the wet decks on boats...

He is wrong!

[skipmac]

Originally Posted by Celestialsailor

He is wrong!

And I do believe you're right.

Have seen boats with completely delaminated decks, soaking wet core and core that has totally disintegrated into wood mush. Doesn't usually get that bad but it is not that rare and can get bad enough that the boat isn't worth fixing.

[skipmac]

Originally Posted by rognvald

Ct 56 is a solid glass boat: hull and deck. Heavy . . . you bet! Dry weight: 61,500 pounds.

Don't know the specifics of the CT but are you sure the decks aren't cored? Even if the decks aren't cored they are teak which I assume uses about 11 zillion screws into the deck to attach the teak.

[Cheechako]

You may find the possibility of a good balsa core is higher in a small trailerable like you are looking for. Especially if you buy one with a trailer. Also, those small simple boats have few thru hull penetrations which makes your odds better.
I know of one C&C Mega 30 that had no hull penetrations but bad blisters and the core was wet... been scratching my head on that one but I guess water can get in the core by condensation? maybe especially on a very lightweight thin hull..?
Yes... they may be lighter boat .. until the balsa absorbs moisture! Also, I've noticed some cored boats have quite thick inner skins... which begs the question... without very good control of manufacturing... are those boats really lighter than a solid hull?

[Sailorman Ed]

Clockwork - I just started removing the waterlogged balsa around all the salon windows (12) on the cheap multihull that SandCrab forced me to buy last year. Looks like the 1/4" bolts holding the windows on were the primary cause. Much of the balsa was wet days after a rain but some sections still were well adhered to the outer skin. Some just mush. I am thinking now to replace with Divinycell. Do I want to remove the windows and place a layer of PE film there and replace? Fill the complete window area and then go back and cut it out or leave the window openings there and taper the inner glass over the cored edges? The only way I see to hold this in place is vacuum??? The area of the decks just below the salon walls also got wet so I must go at least 6 inches inward.

I noticed a couple drips thru the ceiling so pulled the headliner down (fortunately it comes out in sections) and find that the original handrail bolts are also leaking. I have been slowly removing bolts, coring out the holes, fill with epoxy w silica, and then redilling. Works great but is slow going.
Ed

[Dockhead]

This subject has been discussed over and over again, and a trawl through the archives will be rewarding to you. I can't say anything which hasn't been said over and over again, but here goes:

1. Are we talking about cored decks? Or cored hulls? I am only aware of one or two boats which don't have cored decks, and 90% of these are balsa cored, so you really don't have much choice about a cored deck. That is because your deck needs strength which is very hard to achieve without coring, if the deck is not to be ridiculously heavy. As someone above mentioned, coring dramatically increases strength-to-weight of the part which is cored. Balsa, by the way, is stronger than steel on a kilogram-to-kilogram basis (not as strong as fiberglass, however). Unlike foam coring materials, balsa adds structural stiffness and strength to the structure which is cored with it.

2. Cored hulls are different -- many boats have hulls cored above the waterline; relatively few boats, and these days all expensive high-end boats, have hulls cored below the waterline. I am not aware of any Beneteau ever which was cored below the waterline, so if that's what you're looking for and what you are afraid of, you shouldn't have a problem.

3. Cored hulls have a lot of advantages: (a) much higher strength and stiffness for a given weight; (b) improved sound and heat insulation (the latter of which means less condensation). There are two disadvantages of cored hulls: (a) higher cost; (b) risk of leaking and rotting.

4. The answer to disadvantage (b) is to use one of the various methods of encapsulating balsa blocks in resin. Unfortunately, this makes balsa coring even more expensive, exacerbating disadvantage (a). But this is how nearly all modern high end boats (with only a couple of exceptions like Oyster and Nauticat) are cored, cored above and below the waterline. In expensive high-end boats, the cost of encapsulated-block balsa coring is not fatal. Nearly all less expensive production boats use solid fiberglass hulls. That is because this technique, although not as strong or stiff and much heavier, is much more forgiving of small errors of workmanship.


So in short, you probably shouldn't worry about this too much. Some boats were fully balsa cored without good technique and without resin encapsulation -- in the '70's and '80's if I am not mistaken. Some Irwins; some Gulfstars, if I am not mistaken. You might want to avoid these on principle. But you won't find the technique used in less expensive modern boats. And on a more expensive modern boat, you will probably find full balsa coring to be an advantage. So the problem takes care of itself one way or the other.