Thickness of Deck Core?

[Tom Keevil]

We have a bit of saturated side deck that needs to be redone. We'd like to purchase the core material before opening it up. Does anyone know the thickness of the deck core on a CD33? Thanks.

[Frenchy]

It's 1/2". I recently replaced some damp balsa core with corecell along the starboard deck and that's what it was. On
my boat, I'm pretty sure the source of the leak was the eyebrow trim fasteners above the ports. Good luck! - Jean

[Tom Keevil]

Thanks Jean. It never occurred to me that the water could have come from the eyebrow. How does it get to the deck? Is the vertical wall of the cabin cored?

[Frenchy]

Tom, I'm no authority on this, but I think the space between the vertical inner cabin molding and the outside vertical fiberglass is hollow.
The water must seep down in this hollow cavity and come up against the inboard edge of the deck. Cape Dory probably
made an attempt to seal that inner edge of the balsa core with resin but apparently there were gaps.
I have two areas on the starboard side that have damp core, as read by a moisture meter. One is right up forward
along the forward most part of the cabin and the other (now repaired) is by the sunken inner genoa track. That track
area, by the way, is solid fiberglass. So no worries about leaking fasteners destroying core there.
The eyebrow fasteners got special attention and hopefully they won't leak. I think John Stone also mentioned
leaking eyebrow fasteners in his story about rebuilding his CD 36. Hope this helps - Jean

[John Stone]

Yes indeed. I had water streaks down the inside of the cabin top that became visible when I cut the headliner out. 28 holes on each side for the eyebrow trim. I removed the trim and filled the holes. Looks just as nice as it did when the trim was there and varnished. I see no functional value in the trim.

There should be some pictures here:
http://www.farreachvoyages.com/projects ... erior.html

The bad new is that unless you address the source of the leak you may well find yourself back repairing the core later. The good news is that, at least on my boat, it's unlikely that leaky eyebrows trim can lead to water in the side deck as the balsa core does not extend up the cabin side. It's solid glass with a hollow space void between it and the headliner. I'm not saying it's impossible just unlikely. It might be migrating from somewhere else. Post some pictures of your deck unless you have already identified the source.

[Frenchy]

Thanks for your post, John. You've got me re-thinking the source of my deck leaks. I'm thinking that any
leaks from the eyebrow fasteners would send water inside the boat, not into the side deck core. The gap
where the headliner ends inside the boat (near the hull-deck joint) is where the water would probably come out.
Is that right? - Jean

[John Stone]

That's right Jean-Pierre. I don't know how the water would get across the solid glass and then into the coring from under the bottom skin of the cored deck. I suspect it is coming from the bow area and migrating back unless there is a source near by.

[Tom Keevil]

Thanks for your post John. Why do you suspect the bow area as a source of the leak? Our problem areas are near the center of the side decks.

[John Stone]

Gravity. The bow is higher. Perhaps the water has found a channel between the skins then flowing aft till it finds a channel outboard where the gravity of the deck sloping down and outboard has greater influence. On the other hand it may be possible it is coming from the cabin top. Without really looking at it and understanding what is there I can't really suggest more than that. Also, I can tell you how my boat was constructed but not with certainty how your boat was constructed.

I suspect there is a fastener leak somewhere near by. . . but up hill from where the damage is. Water can't flow up, has to go down. For example the PO of the Far Reach had installed little fairleads on the deck, right next to the cabin top, for a jib furler line. All those little holes leaked. The core was damaged near there as it was around the winch bases. I had to recore much of those areas.

Spend some time, if you have not already, just mapping out the area all around the leaks. Also, look inside how the overhead and trim are put together. Maybe there is a way for water intrusion. Thought: the area between the headliner and the underside of the cored deck is a void. Except, it isn't where there is a mastic that fills the gap between the two in random places. Perhaps water is entering in through the cabin top, eyebrows or otherwise, running along the inside top surface of the headliner, making contact with the mastic, pooling until there is enough water (and head pressure) and if there is a fitting in the inside of the boat that penetrates up into the skin from underneath I guess it's possible for water to get into the core that way.

It's a vexing problem to solve and it's why I was so obsessive about eliminating every fastener that penetrated the decks and cabin top.

[John Stone]

Another thought is the stern also slopes down towards amidships. So look around there too . . . winch bases and what not.

[Tom Keevil]

Thanks John for that detailed, and very helpful post. Looks like we have a lot of detective work ahead of us before tearing into things. It's all rather daunting, I admit.