# Balsa Cored hull



## TSOJOURNER (Dec 16, 1999)

As I have mentioned, I am looking at the Tartan 33 (1982ish) as well as the Ericson 34/35. I am onto a beautiful T33, and she is close to pristine for a boat that age. The owner is openly referring to some blisters on the hull, which he acknowledges and says he will adjust price for. This would not necessarily bug me, except for the fact that I recently learned that the T33 has a balsa cored hull. I know that much rests on the depth and or extent of the blisters, but in general, should I be more worried about hull malformations because the hull is cored? Thanks for your input.


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## sailingdog (Mar 19, 2006)

Are the blisters below or above the water line?? Also, did you have the boat surveyed?? If the boat surveys with a dry core in the hull, the blisters are probably just cosmetic. If the survey reveals the core is wet, delaminating or rotting... then it could be a big problem. YMMV.


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## TSOJOURNER (Dec 16, 1999)

SD,
I have not offered on the boat yet. No survey yet. Blisters are below waterline. It will affect my willingness to offer on the boat if the risk of serious hull delamination is higher with the T33 than the E34 which has a solid glass hull.


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## PBzeer (Nov 11, 2002)

There is always a risk with a cored hull, but without a survey, there's no way to know if it's a problem or not.


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## TrueBlue (Oct 11, 2004)

Three seasons ago, my boat was drydocked next to a Nonsuch 30 with a serious below waterline balsa rot problem. The bottom was tented to the pavement, in an attempt to dry out the uncovered balsa. 

I made friends with the owner over a couple beers, who was determined to replace the rotted balsa himself. The more he removed, the more he discovered - ended up removing 80% of the bottom. I returned 2 seasons later and the boat was still unfinished.

I learned enough to establish that a balsa cored hull boat, is a definite deal breaker to me. Nice interiors on those N30s, but - What a project!


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## sailingdog (Mar 19, 2006)

Bardo-

The risk of serious delamination problems is always higher on a cored hull boat than a solid glass boat.


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## TSOJOURNER (Dec 16, 1999)

I get that, SD. But if the hull is well cared for, pulled inspected and treated anually, is there reason to expect that I will have a serious problem later? This presumes that a survey finds the hull sound and dry (other than cosmetic blisters) when I purchase?


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## sailingdog (Mar 19, 2006)

Bardo said:


> I get that, SD. But if the hull is well cared for, pulled inspected and treated anually, is there reason to expect that I will have a serious problem later? This presumes that a survey finds the hull sound and dry (other than cosmetic blisters) when I purchase?


No, provided proper care is taken to avoid introducing water into the hull's cored areas. On one boat I was looking at with a friend...the hull was a bit soggy... and it was because there was a single screw for a wiring harness clip into the hull in the bilge...for a bilge pump...and water had gotten into the core through it...and rotted out about 20 sq. feet of hull. UGH.


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## TSOJOURNER (Dec 16, 1999)

I'm really sad to hear this. I had been tracking on the T33 for some time now, and it all looked good. But I don't want even a fairly low risk of water problems if I can help it. I guess I should opt for a solid glass hull in a similar Ericson.....


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## Valiente (Jun 16, 2006)

Do you live in an area where the boat is likely to freeze in the winter?

Frankly, that's a deal breaker for me, knowing what wet core in deck can do in a freeze...


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## TrueBlue (Oct 11, 2004)

Val,
That's exactly what happened to my friend's boat - ice expanded beneath the balsa & outer ply of GRP, resulting in gross delamination.


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## k1vsk (Jul 16, 2001)

Rather than s[eculate over this, if you really like the boat, why not go ahead and make an offer? Obviously, you are knowledgeable enough to make it with the appropriate contingencies. You could always do your own preliminary hull survey before spending money on a real one. Given the boat isn't new, any latent defects would have already manifested themselves in terms of core issues so if the core is currently sound, all you need to do it keep it that way. Too any people get paranoid over cored hulls which clearly can be a problem but just as often are not.


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## sailingfool (Apr 17, 2000)

The T33 is a nice boat, one of a number of nice options that I eliminated during my last search due to their cored hulls. Not to repeat a tread that has been covered 5-10 times here on Sailnet over the past few years, but I consider a cored hull a big red flag. Most readers can join this attitude by reviewing the screed in http://yachtsurvey.com/structuralissues.htm . The surveyor author makes the point in one of these articles that moisture testing of a cored hull is very inexact, and in fact, a no moisture reading can occur if the core is entirely wet, due to the mechanics of using a meter...

Be that as it may, or may not, the T33 is a nice boat, and the E34 is a nice boat...but given all the issues you inherently take on when you buy any older, used boat, why buy a T33 and the risk of the biggest problem you can face with a boat, when for the same money you can buy an Ericson, just as nice, and never need to worry about the hull? I mean, who needs the risk?

PS - I had this conversation a while ago with a buddy when he was looking at a Hinckley 42, he thought I was going a little bit overboard on the subject, survey was OK and he bought the boat. He came around a few years later when he had to replace all the Airex core in his $$$ boat's hull...expensive and he lost the use of the boat for a year. Like I said, who needs it?


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## NOLAsailing (Sep 10, 2006)

I have a balsa cored hull. I have some experience with recoring and the cored hull will keep you up at night.

A cored hull is a legitimate construction method, but you have to be sure ALL through hulls are properly bedded and, ideally, isolated from the core. Also watch out for the exhaust outlet. Also, you need to check for delamination annually. If caught early, it is an easy fix. Let it go and, well, you're in trouble.


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## TSOJOURNER (Dec 16, 1999)

> I get that, SD. _But if the hull is well cared for,_ pulled inspected and treated anually, is there reason to expect that I will have a serious problem later? This presumes that a survey finds the hull sound and dry (other than cosmetic blisters) when I purchase?


The fact that there are blisters on the hull indicates that the boat has not been well-cared for.

Every boat owner has different standards of decent maintenance. Without knowing the habits of a person you are buying a boat from, you have no way of knowing that their concept of "well-cared for" is the same as yours.

The owner may have spent countless hours cleaning and polishing everything, bought new sails and changed the engine oil regularly... but that doesn't mean that the boat has been maintained.

Without wanting to seem like a wet blanket, any owner of a cored hull, who has not put an epoxy barrier coat on the boat, is either not very knowledgeable or not particularly maintenance-oriented.

If the boat has been barrier-coated already, and there are blisters there again, don't walk away from the boat - run.

If they are new blisters - ask the owner why the boat wasn't given a barrier. THen ask him to describe his maintenance routine in detail. What he did and didn't do will provide a lot of useful information for your surveyor.

Me - I'd keep looking. Good Luck  (I wouldn't buy a cored hull from anyone I didn't know and trust well)


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## TSOJOURNER (Dec 16, 1999)

Thanks for all of the input. I am meeting the owner this morning and may go for a sail. But I will be honest with him and get detail on the maintenance regime and hull issues. We shall see....


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## sailingfool (Apr 17, 2000)

*Get real...*



Bardo said:


> Thanks for all of the input. I am meeting the owner this morning and may go for a sail. But I will be honest with him and get detail on the maintenance regime and hull issues. We shall see....


Bardo,
Get real, if the boat you are looking at has a problem, the bigger the problem is, the more certain it is that the owner will not admit to any, a truly nasty problem that's not apparent will never be mentioned. The seller will hope to be lucky andr that your surveyor is not thorough and that you will take the big problem off his hands, while you happily think you're gettting a good deal because you're paying a little under market. This happens all the time.

if you think anything else, then plan to be quickly seperated from your money.


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## TSOJOURNER (Dec 16, 1999)

We have a balsa cored boat in our local yard that has been on the hard "drying-out" for almost eight years.


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## TrueBlue (Oct 11, 2004)

Don't buy it . . . walk away . . . plenty of solid GRP hulls on the market of similar price and specs as the early '80s balsa hulled Tartans.


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## TSOJOURNER (Dec 16, 1999)

I spent the morning on the T33 with the owner. the boat is in fantastic shape top to bottom. Oh yeah, that bottom. Then I spent the afternoon on an Ericson 34, 1987 model. There is no comparison for me and my family. The Ericson is much better suited to a family, and of course has the solid hull. I will hold out for a clean E34, eighties vintage. thanks for talking me down!


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## Rockter (Sep 11, 2006)

I would be very wary of it. A cored hul, with a coring that rots. Man, that's an idea... brilliant, just brilliant.


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## TSOJOURNER (Dec 16, 1999)

I thought you all might be interested to know....I spoke with Art Averell at Tartan C&C today, and the tartan 33 does not have balsa core below the water line. Only above and towards the bow. This guy is the manufacturing guru for the older older tartans, and his statement is confirmed by a T33 owner who gave me the same information from a visual inspection. So the T33, although not the perfect design or size, may still be in the hunt based on its superb condition.


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## TrueBlue (Oct 11, 2004)

> This would not necessarily bug me, except for the fact that I recently learned that the T33 has a balsa cored hull.


It's good practice to check your sources. It did seem odd to me at first that Tartan would do such a thing. But, Nonsuch used balsa below the waterline, as well as many other quality builders from that era.


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## TSOJOURNER (Dec 16, 1999)

TB,
Too true about sources. I have gotten conflicting information from everyone including the manufacturer. So in fact, I am still skeptical and am seeking another source for confirmation. Some people in this thread said that the T33 had the balsa core, and that it had influenced their decision not to buy the boat. I have T33 owners telling me no balsa below the wl and T33 owners telling me yes. tartan/C&C says balsa above not below. In the case of a boat that is in "perfect" condition for a boat that age (pending a survey of course), and therefore very attractive to me,how would you proceed to resolve my conflict, short of sneaking onto the boat and taking a core sample in the dark of night? Constructive advice would be appreciated.


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## sailingdog (Mar 19, 2006)

Often, you can tell by looking at the hull's interior whether the hull is cored or not. No core sample is necessary. You can often see the core material through the glass laminate over it if you have a strong light source... bringing a good flashlight, digital camera and notebook when you got to look at a boat is always a good idea.


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## sailingfool (Apr 17, 2000)

My knowledge of the T33 is ancedotal so I'm am not certain where its cored. But usually you can tell where there is coring if you can see the inside of the hull. Where there is core, the hull laminate is thicker and where the core abutts solid glass there should be a ridge. During my last boat search we looked at a nice C&C 38 II, when inspecting the cockpit lockers, we saw a ridge on the inner hull below the toerail indicating the boat had a cored hull, so we terminated the inspection as I had thought the model had an a ll-glass hull. Moved onto something else/


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## NOLAsailing (Sep 10, 2006)

> Often, you can tell by looking at the hull's interior whether the hull is cored or not. No core sample is necessary.


How is that possible?


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## TrueBlue (Oct 11, 2004)

NOLAsailing said:


> How is that possible?


Here's an image from a pertinent article by Phil Peterson:








The photo above is from a 34 ft. sailboat, and shows a good example of a balsa cored hull. The square patterns of the end grain balsa core is visible through the translucent fiberglass. Most builders paint the interior areas of the hull so the balsa core is usually not visible. Note the dark square area around the bronze through hull fitting where the builder correctly did not use balsa core to preserve the integrity of the wood and to keep it dry. However, a depth sounder transducer was installed in the balsa cored area to the right of the bronze through hull fitting, which is not a preferred practice. However, the area was inspected using a moisture meter, and no moisture was found, indicating the balsa was still well sealed.

Cored Hulls


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## TrueBlue (Oct 11, 2004)

Sorry about that photo size . . . it's much smaller in the article.


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## NOLAsailing (Sep 10, 2006)

Interesting. Thanks for the clarification. I also just read SD's explanation which I somehow skipped over in the first reading.


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## sailingdog (Mar 19, 2006)

Did you read what Sailingfool wrote?? Didn't think so... 

When a boat has a cored hull, the edges of the laminate generally aren't cored, since they have to have some solid glass areas for the hull deck join and such things like that. If you look at the laminate and it has a area where the laminate gets much thicker, like 1/2" or more, that generally indicates that is where the cored area begins.

To get an idea of what I'm talking about put a telephone book on the floor and cover it with a rug... the rug is the solid laminate, the area where the telephone book is the cored area of the laminate. See how the telephone book causes the rug to rise up... same thing happens in a cored laminate.

Also, as I said previously, in many cases with a bright enough light source, you can often see the texture of the material used as the core, which you wouldn't see if the boat were solid fiberglass. Of course, if the hull's interior is fully gelcoated, you can't use this trick.



NOLAsailing said:


> How is that possible?


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## TSOJOURNER (Dec 16, 1999)

"Coring was used in both the deck and hull and through-hulls were epoxied. The bow is solid below the waterline. Like any classic sailboat, there's the possibility of water intrusion and deck fittings and through-hulls should be checked regularly and repaired properly." This is a quote from the Tartan owners site. Enough said, sorry to raise it up again.
Freeman


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## NOLAsailing (Sep 10, 2006)

> Did you read what Sailingfool wrote?? Didn't think so...
> 
> When a boat has a cored hull, the edges of the laminate generally aren't cored, since they have to have some solid glass areas for the hull deck join and such things like that. If you look at the laminate and it has a area where the laminate gets much thicker, like 1/2" or more, that generally indicates that is where the cored area begins.
> 
> ...


That's really interesting and not something that I've noticed before. I have a balsa cored hull and deck and I'll have to check that next time I'm digging around in one of the lockers. I know there is core there, of course, but it will be interesting to see if a light source will illuminate the balsa squares beneath the laminate.


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## T37Chef (Oct 9, 2006)

*Challange*

Okay, so here is the challange...all this talk...so provide proof of *ANY* Tartan, and more specifically a T33, of that era that has had "serious delamination problems" because I cant find one and would be curious to know.


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## TSOJOURNER (Dec 16, 1999)

It may be in great shape, but then again it might not. If the boat was not blistered, I would be more inclined to give it the benefit of doubt, but the blisters COULD indicate that the current owner didn't take great care of the boat (it's not definite, but it's a possibility).

Then there is also the factor of the propective purchaser's level of experience. Chances are that there will be some errors and a learning curve, through absolutely no fault of his own. We all make mistakes.

So, combining the POSSIBILITY of a bit of neglect, with the POTENTIAL hazards of a wet core, and an new owner who is new to maintenance...it seems that there are enough negatives involved in the equation to give one pause...

If Bardo were to keep looking, and find a solid cored boat, that had no blister issue, then he has eliminated two out of three 

Please don't take offense here Bardo...we are all on a learning curve


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## sailingfool (Apr 17, 2000)

*Take it to the Tartan Board*



T37Chef said:


> Okay, so here is the challange...all this talk...so provide proof of *ANY* Tartan, and more specifically a T33, of that era that has had "serious delamination problems" because I cant find one and would be curious to know.


Certainly a better question to take to the Tartan board, but I gotta ask you - if a friend's Hinckley SW42 needed to be recored, what makes you think Tartan is somehow immune?


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## TSOJOURNER (Dec 16, 1999)

Well,
Seems I have struck a nerve. Sailormann, no offense taken. I have never put myself out to be too salty on the maintenance side. I have to learn the ropes too. Your points on eliminating the risks that can be eliminated are good ones. However, I HAVE taken this to the tartan owners sites, both on yahoo and on the tartan owners site, and have so far come up with not one tartan that had a problem like the one described in the surveyor's thread. Not saying it couldn't, or even won't happen. Just that I havn't found one yet. And while I am not as experienced as you salty dawgs around here, I'm not stupid, nor did I dip my toe into salt water just yesterday. So I understand the requirements of maintaining a hull of whatever composition (not that I would replace a through hull by myself yet). BTW, one positive note on the Tartan cored hull is that they did epoxy around all of the through hulls, so "at least we got that goin' for us...". Final note: I wouldn't be having this conflict if it weren't for the obvious good condition of the tartan boat. Many have said here that it often comes down to how a boat has been cared for. The blisters on the bottom of this T33 were deemed cosmetic by a surveyor last season. That is why the guy has not repaired them yet. Planned for this year after its pulled. This is one of those rare boats (in my limited experience) that has been really kept up to the highest standards (survey pending of course). So thanks for all the input, and God only knows what I'll do. But I'll keep putting myself on the line here because its a great place to learn!


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## T37Chef (Oct 9, 2006)

sailingfool said:


> Certainly a better question to take to the Tartan board, but I gotta ask you - if a friend's Hinckley SW42 needed to be recored, what makes you think Tartan is somehow immune?


I poss the question here because so many here *seem* to be experts on the disadvantages of a cored hull and I want to know why other than the "possibility" of core damage. The question has been asked on the Tartan site, but we are discussing it here at the moment. I think I can safely say that thousands more sailors visit Sailnet daily than any of the Tartan sites combined?

I *NEVER* said I thought Tartans were immune, or implied it, but it seems you are. I just want to know how many of the hundreds of Tartans built with cored hulls have had serious cored delam.


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## T37Chef (Oct 9, 2006)

sailingfool said:


> if a friend's Hinckley SW42 needed to be recored, what makes you think Tartan is somehow immune?


And...

I suppose this proves that any boat....no matter what the brand, if not cared for, will result in a problem or two...


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## NOLAsailing (Sep 10, 2006)

Whether or not a cored hull is advantageous depends on what the boat was designed for. A cored structure is lighter and more rigid than one made from solid laminate. It's only significant drawback is the potential for rot caused by water intrusion. In all but the worst cases, this is a fixable problem. It's also something that can be prevented by careful maintenance.

A solid FRP structure can still delam and have voids in the layup.


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## camaraderie (May 22, 2002)

Jason...in a cruising situation, the *other* drawback of a cored hull is the difficulty in getting repairs done if the boat is holed or run aground and has damage. You can get plain old fiberglass fixed anywhere but repairing a cored hull is not a job for amateurs.


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## robinhc (Oct 9, 2016)

Bardo said:


> I get that, SD. But if the hull is well cared for, pulled inspected and treated anually, is there reason to expect that I will have a serious problem later? This presumes that a survey finds the hull sound and dry (other than cosmetic blisters) when I purchase?


What you see may not be what you get!

As long as it is not a cored bottom you can grind off the blisters, get rid of the styrene and then over a couple of weeks wash the hull and scrub with Dove etc and then check her with a meter until she is dried out. You may then mix up an epoxy with fairing microballoons and once sealed and faired coat the whole bottom with e2000.

However with a cored hull. If the core is wet and has no epoxy saturation, you will find that the internal core has probably turned to mush as a result of the hull slamming into a short sea. In short run away and leave it for a person who wants a comfortable cottage!


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## T37Chef (Oct 9, 2006)

Lets see, my Tartan has a balsa cored hull from the waterline up, its a 1982, 34 years old... been sailed hard... hull is dry... probably fine for another 34 years. 

Solid vs. Cored is a ridiculous debate IMO... but then again I'm no navel architect or marine surveyor.


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## T37Chef (Oct 9, 2006)

Ha... this thread is old!


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## Capt Len (Oct 9, 2011)

Only 9 years , it's time for Bardo to surface from his recoring job and tell us it is going to be worth it.


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