replacement for ply bulkhead

[Adyy]

I have a rot problem in a structural bulkhead. (between cabin and engine room)I found a product that may be helpful to replace the 3/4" ply but I'm concerned about the strength.
here's a description:
Cana-Core Honeycomb is a lightweight corrosion, rot and chemical resistant product used in sandwich panels, or any other area where a honeycomb product with a high strength to weight ratio is required.
Fiberlay
Anyone have an opinion?
Thanks

[roverhi]

Have you priced it??? Hard to beat plywood for cost and availability. Seal the edges with epoxy before laminating in place, fix the leak, and should be good indefinitely.

If you've got a multi hull or ultra light sled and have a weight Jones, might be worth exploring this material.

[robert sailor]

Originally Posted by roverhi

Have you priced it??? Hard to beat plywood for cost and availability. Seal the edges with epoxy before laminating in place, fix the leak, and should be good indefinitely.

If you've got a multi hull or ultra light sled and have a weight Jones, might be worth exploring this material.

Agreed

[minaret]

Use Coosa board instead.

[UNCIVILIZED]

Check the sheer strength of this stuff vs. other structural cores, & see how it stacks up. If those numbers check out, then with some work, then I'd say that yes, it'd be viable... assuming that you laminate on sufficiently strong, & impermeable structural skins.

Plus, anywhere that there's going to be an opening in it, as well as all around the edges, & anywhere there's a fitting, you're going to need to fill in the edges of this core, & also put in solid material. Like G10, Wood, Plywood, etc.

Here are a couple of relevant threads on the topic, & the material. Including one where I made some inquiries about Nida-Core, a similar, if not the same material, only rebadged. On bulkhead construction, including composite bulkheads.
Bulkhead repair - Fix It Anarchy - Sailing Anarchy Forums=
On Nida-Core Nida-Core: Looking 4 Thoughts & Feedback - Boat Design Forums

The thing is, unless you Really need to save weight on the boat, using this stuff for one part, is likely both going to cost you more, & be a heck of a lot more work to fabricate, as well as install.

Probably the best way to go is to get some Marine Plywood &;
Cut it to size.
Heavily saturate the edges (especially the lower ones) with a penetrating epoxy.
Glass on a thin layer of fiberglass on each side, & apply enough resin to fully seal both the wood, & the glass.
Properly bed the bulkhead, & tab it into place.

[Cadence]

Originally Posted by Adyy

I have a rot problem in a structural bulkhead. (between cabin and engine room)I found a product that may be helpful to replace the 3/4" ply but I'm concerned about the strength.
here's a description:
Cana-Core Honeycomb is a lightweight corrosion, rot and chemical resistant product used in sandwich panels, or any other area where a honeycomb product with a high strength to weight ratio is required.
Fiberlay
Anyone have an opinion?
Thanks

Stick with the ply. I would not be sure the Honey comb product is meant for lateral compressive strength. Some one had suggested epoxying the butt edges before tagging ply into the hull. You might consider West System or System Three on both surfaces also.

[sailing mike]

Addy, from a structural point of view. 3/4 ply is quite a serious bulkhead. Designed to take a certain loading. I recommend you call the Coosa guys and ask them for a recommended thickness of their panels. I would replace plywood with Coosa! With not a second thought. The strength is greater thickness being equal and the weight saving is very dramatic. Have a look on their site. You can pick up an 8x4 by 3/8 panel with a finger and thumb of one hand....
Regards Mike on Captain O'Brien


Sent from my iPad using Cruisers Sailing Forum

[minaret]

Originally Posted by sailing mike

Addy, from a structural point of view. 3/4 ply is quite a serious bulkhead. Designed to take a certain loading. I recommend you call the Coosa guys and ask them for a recommended thickness of their panels. I would replace plywood with Coosa! With not a second thought. The strength is greater thickness being equal and the weight saving is very dramatic. Have a look on their site. You can pick up an 8x4 by 3/8 panel with a finger and thumb of one hand....
Regards Mike on Captain O'Brien


Sent from my iPad using Cruisers Sailing Forum

And it will never rot. Non decorative organic materials on a boat are SO 20th century. Join the 21st already!

[Vivamus]

I just replaced a bulkhead with 3/4 in pressure treated marine plywood I bought from Overtons. I may have an extra sheet, I will check if you are interested. I live in Hampton Va at the mouth of the Chesapeake.

[Boatyarddog]

Just a quick note, if you did fix the rot problem, did you address the reason it rotted out?

I'm just finishing up on my rotten bulk head issues, it's happened because of leaking deck seams that weren't addressed.
He water was pouring into a"channel"or two that were in the liner, and directly onto and under them.
Fix the leaks, first.
3/4 marine ply is incredibly strong, to compressive loads, especially if the loads are on the edge of the ply.


Sent from my iPad SV Cloud Duster

[Adyy]

P { margin-bottom: 0.08in; } Thank you all for the thoughtful replies.
Background I should have included in the original post:
I have a 37' Cooper Seabird, a fiberglass single hulled center cockpit ketch. Deck leaks accumulated in a vault containing the water tank below the galley soles on the starboard side which was not drained properly ( as in not at all).
The vault is:
3" of glass over ply on the forward side and down the centerline,
the hull on the outside and
a 3/4” ply wall glassed to the hull on the aft end which is the bottom of the bulkhead between the cabin and the engine room/ cockpit.

The floor and soles rotted so I removed the galley, soles and floors, cut and fitted the floors and ply before I found the bottom of the bulkhead was (as wood is prone to do) trying to become humus again.
This bulkhead is seriously important hence my concern about honeycomb materials.
As much as I was interested in rot proof material, I will stick to marine ply for the repairs. The leaks are being resolved but more importantly the limber holes that should have been there and a new forward bilge pump and new pump well will keep any water from accumulating.
Thanks again