Balsa Core

[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

[skipmac]

The positives, balsa core in fiberglass construction will yield a stronger, lighter and stiffer hull than solid glass.

The negative, as you note, if it gets wet in the core then the balsa can rot and the layers of glass and wood delaminate.

The prevention, every where the fiberglass skin is penetrated the hole is overdrilled IE the hole made larger than the bolt or screw needed, then refilled with epoxy and the smaller, proper sized hole drilled. That way the balsa is completely protected from the possibility of water damage.

Can be done in an older boat as well if all the deck fittings were bedded well and the core not wet or even if the core is wet if the damage is not bad and the moisture hasn't spread too far.

I have had two boats with balsa cores, the current one 30 years old with some wet spots but am drying and filling them one by one. The worse were the stanchion bases which take a lot of stress and break the seal of most caulking over time.

[Ernest Skublics]

Thank you Skipmac! Your experience is certainly very helpful. But I am still nervous about acquiring an older boat with balsa core. I have even read that most marine surveyors cannot tell you with certainty that there is no water in the hull. Anyway, Many Thanks!
Ernest

[sailr69]

Originally Posted by Ernest Skublics

Thank you Skipmac! Your experience is certainly very helpful. But I am still nervous about acquiring an older boat with balsa core. I have even read that most marine surveyors cannot tell you with certainty that there is no water in the hull. Anyway, Many Thanks!
Ernest

there are abbott boats ( 33) (36) that are solid fiberglas and I have owned one and raced it. never any core problems. strong boats\

[neilpride]

Old balsa hulls are a Russian roulette, i mean you can found one in excellent condition and lots in terrible condition, all depend of the care of previous owners, i own in the past a balsa cored hull for 12 years, a C&C 40 , surveyor dont found nothing wrong , hahaha all say the same , my first boat and 3 years later a huge bill in epoxy, fiberglass and lots of new balsa here and there, very sad , the boat sail fantastic and i swear i love that boat, but i cant live with balsa, saying that there is no reason for own a balsa cored boat and get the same problems, i see 20 years old hulls in excelent condition, sound and dry, a really good surveyor if you can found one hehe can tell you if is worth or not, same for decks , if you found lots of weird deck hardware fited without care , suspect, moisture meter hull and deck is mandatory, the funy small hammer to, dont be afraid from a cored hull , you just need to found the right one.. good luck.

[belizesailor]

Properly built and maintained, not a problem. Issues are usually caused by PO's not properly bedding holes they cut in the deck.

[skipmac]

Originally Posted by belizesailor

Properly built and maintained, not a problem. Issues are usually caused by PO's not properly bedding holes they cut in the deck.

POs or the original builder.

[skipmac]

Hi Ernest,

You are certainly right to be concerned about problems with a balsa core but the problems are well understood and can be dealt with, starting with a very careful survey of a prospective purchase.

First a good surveyor should have a moisture meter to do an initial check of the decks and hull. However a moisture meter is not infallible and can give false readings but so far in my experience the meter does not miss areas that are truly wet. Also, as you mentioned, sounding the boat with a hard rubber mallet is another test.

If you find a boat you like and have concerns about wetness in the decks I would ask the sellers permission to remove some of the hardware in suspect areas to check. Use a small screw driver or a piece of coat hanger wire to probe down in the hole to see what comes up. If you are a serious buyer and are paying for a survey or have a formal offer in on the boat I think the seller should agree. Of course you assure the seller that the boat and hardware will not be damaged and will be properly reinstalled if you decide not to buy the boat .

Even if you find some wet spots, if not large, they are DIY repairable at a reasonable cost, moderate amount of time and the job does not require super boat fixer skills. I would make note of any problems to the seller and make my offer to account for the repairs. If done the way I mentioned before you have a permanent, solid repair.

[a64pilot]

Balsa is not the only material that is used, there are even some hydrophobic fillers

[skipmac]

Originally Posted by a64pilot

Balsa is not the only material that is used, there are even some hydrophobic fillers

Yes there are other materials used for core but not common on production boats. For an older, used, production boat I would guess 95% of cored boats will be balsa or plywood.

[HappyMdRSailor]

Ernest,

This is something not to:
1. Make it take longer for you to get a boat...
2. Anything to lose sleep over...

99% of the boats out there have cored decks for a reason... It works...

99.9999% of the boats that have "problems" with cored decks are due to improperly installed or maintained deck hardware...

Find a boat without deck problems, do some preventative maintenance... And you'll be able to have a cored deck boat with no problems past when your grandkids are geriatric !!!

GO BUY YOU A BOAT AND GET SAILING!

[a64pilot]

After looking at quite a few boats myself, and finding in at least most of the older gals a lot of core / soft deck issues, I started looking at much newer, slightly smaller boats that fit my budget, low and behold even on a 6 yr old boat, we found a couple of spots that pegged the moisture meter.
I came to the conclusion whether right or wrong that if you have a hydroscopic core, its a matter of time, eventually you will have water intrusion, and damage, sort of like having a car up north, if you drive it in winter, rust is inevitable.
Between that and a non-removable keel, deep bilges and a few other things I wanted, it really narrowed the options, but there are boats out there that do not have wood cores.
Your probably right about the 95% comment, but that still leaves 5% that don't, find out which ones are that 5% and be prepared for a lot of searching. I have never "shopped" for anything like I did for this boat, I'll tell you more than once I was ready to give up, but what your looking for is out there somewhere.

[Island Time O25]

A boat builder friend of mine once told me not to be too afraid of the wet decks on boats with keel stepped masts as long as the chainplates are solidly attached and bulkheads are dry. He said that even in her wet deck state such a boat will most likely outlive her owner.

[clockwork orange]

As a boat builder I have recored dozens of boats, both hulls and decks. The problems of wet core is never the fault of the balsa itself, it is an excellent core material in the hands of a competent builder. In my experience, while the boat owner is often to blame for adding or moving hardware and not installing it correctly, in just as many instances, low quality original build practices are to blame, older J boats are particularly poorly built imho, C&Cs also although I once owned a 1980 C&C 24 that had virtually no issues. This may be a reasonable choice for you as the reason mine was not wet is that, unlike the larger models the hulls are not cored and they have a lot less deck hardware to potentially leak, ie, no genoa tracks although a lot will have owner installed tracks. The only moisture in my boats deck was around the mast base which for me was not an issue as i was installing a J24 rig which was 19" further forward so i just installed a 10" Lewmar hatch where the mast used to be.
As a potential buyer, even if you use a surveyor you need to be sure that he pays particular attention to potential wet core issues, your hull and deck are the most important parts of the boat, a lot of people are dazzled by fluff like electronics etc when in fact anything that is just bolted on is not very important at all as it is easily replaced but if you need to pay someone (like me) it is easy to exceed the value of the boat in repairs in an older boat. If you can find a boat that was cored with foam you will be much better off but unfortunately there are not many out there, they can still get wet core from the usual leaky hardware but I have yet seen it cause any problems and, unlike balsa, if you can dry it out it is as good as new. I have a Lindenberg 26 that has foam in both the hull and deck (other build issues though), and the Macgregor 36 catamaran i used to own had klegecell foam cored decks and was one of the few boats i have encounted from any builder where all proper building practices were used so, consequently had zero deck issues. Incidently i have seen serious wet cores caused by poorly installed snap fasteners used by the canvas guy installing dodgers etc so its not just the boat owner and builder at fault, i have yet to see a canvas worker over drill and pot a hole when installing their hardware, usually just a dab of caulk. So, Beware.
I know this all sounds dire but the truth is most boats have balsa core somewhere so my suggestion is for any buyer to go to home depot and buy your own Ryobi moisture meter for $49 and learn to use it, it is an excellent tool comparable to the expensive ones your surveyor will use, and will allow you to double check his work. This tool along with a plastic hammer will allow you to keep an eye on things even with the boat you already own.

Steve.

[a64pilot]

Originally Posted by clockwork orange

This tool along with a plastic hammer will allow you to keep an eye on things even with the boat you already own.
Steve.

That I think is key, this is like Cancer sort of, if you catch it early it's a whole lot easier and less expensive to fix.
It may be silly, but I intend to do an "annual " inspection on my boat, where once a year the structure is inspected by me to the best of my ability, I think I will head off a lot of problems that way.