Beginner question on fixing damaged balsa core

[Rohan]

OK, after chartering/borrowing/sharing boats for years I'm finally buying my own. I never really had to worry about maintenance before.

I'm purchasing a Hunter 36. This model is full glass below the waterline, and balsa core above.

A surveyor went over the boat and told me that it most likely has moisture inside the core along the starboard side of the hull. He can't say for sure, but by tapping on the hull, he found several areas that sound inconsistent (he also checked another boat of the same model for comparison). His little electrometer also suggests moisture inside. He says it most likely got in through the edges of the portlight.

He doesn't think it's a terrible problem right now, but he recommends sealing it up so that no more moisture gets in.

OK, this leads to my questions. I asked these of the surveyor too, but he wouldn't give me a clear answer:

1. Worst case scenario - if we were to do surgery, and replace the core, what would something like this potentially cost to fix?
   
2. I can revise my offer on the boat after the survey. In my situation, if all other things are fine, would you still buy the boat? What kind of reduction in price would you ask for?
   
3. Instead of just sealing up the leaks, wouldn't it make sense to drain out all water and use some kind of air dryers first?
   
4. And if I just ignored it and it went untreated - what is the worst that could happen?

Thanks in advance for any help.

[Jim Cate]

In your place I'd withdraw the offer and move on to another boat. Wet core in the deck is not too hard to deal with, but in the hull it is a serious problem. And with the survey unsure of the extent, well, it could be less... or a LOT more.

The strength f the hull depends upon the bond between core and skins. When the core is wet it rots and the bond disappears entirely in that area, generating a weak spot or area in the hull, and that's something I'm not prepared to risk myself.

There are a lot of boats for sale these days, boats with sound hulls.

My non-professional opinion, but backed with some experience.

Jim

[S/V Illusion]

We once owned a H 40.5 with a void which never expanded in size over the 10 years we had her.

[Lake-Effect]

Originally Posted by Rohan

A surveyor went over the boat and told me that it most likely has moisture inside the core along the starboard side of the hull. He can't say for sure, but by tapping on the hull, he found several areas that sound inconsistent (he also checked another boat of the same model for comparison). His little electrometer also suggests moisture inside. He says it most likely got in through the edges of the portlight.

Possibly a longshot, if sealant has glued the thing in place... but would it be possible to remove the starboard portlight without damaging hull or portlight, and inspect the core at that point?

[Pegu Club]

What Jim said, lots of boats out there that are structurally sound. Don’t start out behind the eight ball.

Fair winds,

[coopec43]

Originally Posted by Pegu Club

What Jim said, lots of boats out there that are structurally sound. Don’t start out behind the eight ball.

Fair winds,

I agree with Jim and Pegu.

You could cut out the inner fiberglass lay-up, replace the balsa core and re glass that area but where do you start as even the surveyor is vague?

Get a solid glass boat: that is the way to go.

[Tillsbury]

Nothing wrong with a well built boat that's cored above the waterline, but what you're looking at isn't one. Move to the next boat and thank the surveyor for how much he saved you.

[Rohan]

Thank you for the replies! Other than this problem, the boat is in almost new condition all around and has everything I want. So I'm willing to consider having this problem fixed.

But the problem is, I need to know how much it would potentially cost. In your opinions, what would be the maximum ball park estimate I could expect to replace the core along the front half of one side of a 36' boat? $1000? $20,000? $100,000? I really have no idea.

[malbert73]

Wild guess is 20-40K depending on how much interior needs to be removed for access to inner skin...

[LittleWing77]

Ugh. There are Hunter 36s for sale everywhere. They're production boats. Get yourself one that doesn't have a core problem!

Fair winds,
LittleWing

[coopec43]

Originally Posted by malbert73

Wild guess is 20-40K depending on how much interior needs to be removed for access to inner skin...

Probably chucking good money after bad. But if that is what you want to do!

[Toccata]

Rohan
Having restored too many boats for my own good...please listen to the experienced messages here advising you to walk away from that boat.
It will cause you untold grief
It will cost far more than you expect
You wont be using it, you will be fixing it for far longer than anyone can estimate
It will burn you and burn your enthusiasm for boating
Just don't do it to yourself and family
Find a good one.

[Suijin]

Originally Posted by Rohan

But the problem is, I need to know how much it would potentially cost. In your opinions, what would be the maximum ball park estimate I could expect to replace the core along the front half of one side of a 36' boat? $1000? $20,000? $100,000? I really have no idea.

Reglassing 18' x 3' along the side of a boat? A lot.

As Jim pointed out, the strength of the hull is a function of the bond between the inner skin, the core, and the outer skin. If the core fails, then an integral part of the structure is gone. Like an Oreo cookie where the cream has melted out.

If you took this to your average yard it would be months of work for a worker charging $100/hr. Ten of thousands of dollars.

As to whether it's worth fixing, that's a function of what your plans are for the boat and how cheap you can get it for. If you just want a weekend boat that you'll use 5 months a year, for a few years, and you can get it for a song, maybe it's worth the risk.

Personally I would look for another boat. Don't let cosmetics and equipment blind you to serious structural (and invisible) defects to a boat.

[Toccata]

At resale time, the fixed up boat will always be known as "that boat with the wet core problem"
At least in any smaller community.
The other problem, as pointed out above, What is the true extent of the wetness? I reckon No Surveyor would definitively say that it's limited to a particular area. This issue will be an ongoing problem in that boat.
Really negative? Yep! because we have all been caught by unknown, extensive, expensive boat dramas.
Heed the warnings Rohan

[Pete O Static]

I have to agree with Jim and company. You have two major things working against you.

1) The surveyor thinks the moisture may have started at the portlight. If that is the case, it will likely happen on the other side as well, if it hasn't started to already.

2) Sorry to say but Hunter is not what many would consider a quality builder. Case and point, the portlight. A quality builder would never run a balsa core to a portlight edge without having a substantial epoxy barrier between the portlight edge and the balsa core itself. Portlights will leak, just a matter of when. The core should always be isolated from any potential leak points.

You could contact Hunter and ask if the core is protected around the portlights but In my opinion, you could potentially spend a ton of money to fix the issue at hand only to have it repeat elsewhere on the boat. The only reason the integrity of the core should be compromised is from a collision or other such damage. Maybe this did happen at some point and a very good cosmetic job was done?