Change to foam coring in decks, etc.

[nor'easter]

I had a 1995 hatt and the decks were foam cored. When did hatt change to this process? Late 80's? I know the cored bottom 41 was a late 80 s boat, so maybe then? Curious about the late 80s (87 and later) 45 C and whether they would be immune to the cored foredeck soaking that many mid 80s and earlier boats get.

Thanks
Paul

 

[Maynard Rupp]

Closed cell foam coring material does not soak up water. It has been known to come unglued from the inside of the deck or hull if flexed too much. Balsa core adheres perfectly but will rot if water is allowed to get to it. The best answer is balsa with all holes oversized, plugged with thickened epoxy and re-drilled. My Hatteras manual shows a procedure for correctly adding a through hull fitting in a cored area.

 

[nor'easter]

I agree, but clearly on boats of this vintage its an issue. I was just curious as to when the change may have occurred.

 

[lumina]

Hi All,

Our 1974 Yachtfish had some type of foam cell core in the cockpit. As Maynard mentioned, the core didn't soften or degrade it came unglued.

Replaced with divinycell.

 

[Vincentc]

Water damaged balsa coring has caused me to spend a lot time working on our boat; but I agree with Maynard, that balsa provides a good composite core so long as water is kept from it. I have seen water in the foam cored transom, and while the foam does not rot, it does not appear to adhere very well to the frp skin.

Like so many things, IF you treat it properly protecting it from water intrusion via penetrations, balsa coring will work very well. In boat as old as ours, chances are, one or more of the previous owners or their contractors did not exercise that requisite care.

regards,

 

[nor'easter]

Seems like balsa is a great core material, and i agree.

Maybe i will call sams or try and reach roger worthington and see is anyone recalls. I would expect it would be different model to model as well.

 

[lumina]

Hi All,

FWIW, given all of the advancements in technology and new coring products available I'm not sure balsa makes sense. As I mentioned we used divinycell and we're extremely happy with its strength and adhesion properties as well as it being extremely easy to work with, cut and and fit.

It could be that balsa has been improved through advances in technology as well, but it seems it's as susceptible to water as it ever was.