Hull construction is it made full fiberglass or sandwich ??

[Freddy rizk]

I would like to know about the 2 sides of the hull of kelt 7. 6  are they made in a sandwich or just full fiberglass thanks

[Ryan]

Hi Freddy,

Having just put a few holes in my Kelt I can tell you that it's a sandwich construction at the base of the mast.  I'm not sure if the whole boat is built this way.

Ryan

[Mark Williamson]

According to the brochure:  "The hull is hand laid up mat and roving fiberglass which provides a solid hull capped with a bonded and bolted Klege-Cell sandwich deck.  Maximum hull thickness averages 7/8" in the keel area."

No balsa core in the deck so no rot and soft spots.

[Ryan]

I know this is a bit of an old post but I thought I'd share what I've actually seen on my boat in terms of deck core construction.  At the mast I installed a VHF cable and can confirm I drilled threw wood.  I also recently installed new deck organizers and clutches and again drill through wood. I'm pretty sure it was balsa.

On a related note, does anyone know how thick the core is where the head sail traveller is?

[Ryan]

In doing a bit more research I found this post on an old forum by an original owner who says the deck is foam but the deck fittings (i.e. mast area, clutches, etc) are 9/16 inch mahogany plywood backing plates.

http://forums.voileabordable.com/read.php?2,1029,page=1 

[gandalf]

I know this is an older post, but in doing some of my own research, I've found three different sources stating the deck is made of three slightly different foams.

1. From the user manual: urethane foam sandwich

"The deck features innovative construction techniques far ahead of the competition. All traffic areas are reinforced with high density aircraft grade urethane foam sandwich. When this material
is combined with the hand laid fiberglass mat and roving, an exceptionally strong yet lightweight
deck is the result. In addition, all deck fittings have inlaid 9/16 inch mahogany plywood backing
plates to spread the load and withstand compression."

2. From the boat of the year 1980 article: Klege-cell

"The hull is all hand laid up mat and roving fiberglass which provides a solid hull capped with a bonded and bolted Klege-Cell sandwich deck. Maximum hull thickness averages 7/8" in he keel area"
Source: https://www.hisse-et-oh.com/store/medias/sailing/5dd/254/603/original/5dd2546039819f3668e3537c.pdf

3. From Canadian Yachting's May 1983 Issue: Divinycell sandwich
"The deck itself is a Divinycell sandwich with stress points reinforced by wire mesh."
Source: https://canadianboating.ca/boat-reviews/kelt-7-6/ 

My understanding (as a non-chemist) is that klege and divinycell are PVC-based, which would be different from the urethane foam. Thoughts on what material was actually used? It could also be that French-built vs Canadian-built or early vs late models used slightly different core materials. Either way, it seems like the core may be able to absorb a small amount of water, but won't rot.

Has anyone had any issues with moisture in the deck around fittings, especially in climates with a lot of freeze/thaw action?