KK42 Deck core

Giday. I've read somewhere that Kadey Krogen 42's changed the deck layup in 1985.

This was an article of collected historical features I found hereabouts somewhere.

It stated that the deck structure changed from a glass over ply composite to something described simply as a "cored composite", iirc.

Can anyone clarify what, in fact the deck structure changed to in '85?

Cheers in advance,

Mark W.

Most production boats would have balsa if talking core.
Pretty rare for them to pay the extra for divinycell or termanto..

Mark: The KK42 fore decks, aft decks and side decks were plywood till hull number #165 when they went to balsa core on the fore deck. I’ve head that they may have used 4”X4” plywood squares but I can’t confirm that.

Our hull number is 120 and completed in late 1987. I’ve drilled into the decks and they are plywood sandwiched in between fiberglass on Hobo.

Simi 60 said:

Most production boats would have balsa if talking core.
Pretty rare for them to pay the extra for divinycell or termanto..

Click to expand...

Thanks. As a matter of interest would divinycell perform as well as balsa in a deck application? I guess it's compression strength would be lower, and adhesion may be less strong? Edit: doesn't rot though...

Larry M said:

Mark: The KK42 fore decks, aft decks and side decks were plywood till hull number #165 when they went to balsa core on the fore deck. I’ve head that they may have used 4”X4” plywood squares but I can’t confirm that.

Our hull number is 120 and completed in late 1987. I’ve drilled into the decks and they are plywood sandwiched in between fiberglass on Hobo.

Click to expand...

Thanks Larry, are you aware if there's any particular areas where they tend to fail? I mean making a perfectly good waterproof membrane over ply or balsa and then riddling that with screw holes to hold teak down provides plenty of scope for water intrusion, but is there a KK42 specific "problem area"?

Mark W said:

Thanks. As a matter of interest would divinycell perform as well as balsa in a deck application? I guess it's compression strength would be lower, and adhesion may be less strong? Edit: doesn't rot though...

Click to expand...

Divinicell comes in different compression ratings. I've made various deck hatch covers with it. The most agressive was a four foot long by 14" single piece that spanned over 3 feet with only end supports. It was a walkway topsides!

Simi 60 said:

Most production boats would have balsa if talking core.
Pretty rare for them to pay the extra for divinycell or termanto..

Click to expand...

My Bayliner 4788 has a composite deck core, no balsa, nothing to rot.

ksanders said:

My Bayliner 4788 has a composite deck core, no balsa, nothing to rot.

Click to expand...

Plywood core glassed over is composite
Balsa core glassed over is composite
Cedar or other timber strip glassed over is composite
Newspaper and snot is technically composite.
Are you sure yours is foam?

Simi 60 said:

Plywood core glassed over is composite
Balsa core glassed over is composite
Cedar or other timber strip glassed over is composite
Newspaper and snot is technically composite.
Are you sure yours is foam?

Click to expand...

Yes, 100% foam deck core.

ksanders said:

Yes, 100% foam deck core.

Click to expand...

Nice

My 1981 boat has a foam core. So does Brisboy`s 1983. It`s been in use a while. But relevantly, not in KKs,so please excuse the drift.