Re: [Cal_Boats] Bulkheads

Chris: Thanks for the feedback, I actually know very little about what woods are good for interior boat work - my main concern lies in the materials for the bulkheads, because of structural integrity. What is recommendable? I'd like light wood, as I plan to change to a clearer interior. Again, feedback is appreciated! All the best Jeff From: Chris Campbell <cl… [at] charterinternet.com> To: Ca… [at] yahoogroups.com Sent: Monday, September 8, 2008 11:03:31 AM Subject: Re: [Cal_Boats] Bulkheads Jeffrey owen wrote: Good morning Hope all is well, I have been enjoying the posts and printing some for future reference. Anyway, to the point. I have been replacing sections of deck core with marine plywood. I am almost done with that, and now will begin bulkhead replacement. I plan to use red oak laminated plywood, but would like to know if that is recommendable. Jeff: As you probably know, red oak was disfavored traditionally as a boatbuilding material because of its pore structure, which favored movement of moisture and rot spores in the wood, leading to early failure. There's also an issue of the effect of oak's tannins on the cure and strength of epoxy. My guess is that the plywood has oak veneers only, with some other core plies. In that case, you could seal the edges with epoxy successfully. If the red oak veneers didn't interfere substantially with epoxy bonding (go look at the Gougeon Bros. web site and see what they have to say), then it's probably not a problem. Chris Campbell

I have used OKUME Plywood in the past. It is Lloyds of London A1 rated, very strong with nicely finished covers.

That's the word! That's the word! Couldn't remember for the life of me. Wudda spelt it wrong anyway. Cheers Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of ti… [at] ch2m.com Sent: Monday, September 08, 2008 1:15 PM To: Ca… [at] yahoogroups.com Subject: RE: [Cal_Boats] Bulkheads - OKUME I have used OKUME Plywood in the past. It is Lloyds of London A1 rated, very strong with nicely finished covers.

(I spell it worng too) :) From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Husar, Charlie [USA] Sent: Monday, September 08, 2008 10:57 AM To: Ca… [at] yahoogroups.com Subject: RE: [Cal_Boats] Bulkheads - OK O UME That's the word! That's the word! Couldn't remember for the life of me. Wudda spelt it wrong anyway. Cheers Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of ti… [at] ch2m.com Sent: Monday, September 08, 2008 1:15 PM To: Ca… [at] yahoogroups.com Subject: RE: [Cal_Boats] Bulkheads - OKUME I have used OKUME Plywood in the past. It is Lloyds of London A1 rated, very strong with nicely finished covers.

Jeffrey owen wrote: > Chris: > > Thanks for the feedback, I actually know very little about what woods > are good for interior boat work - my main concern lies in the > materials for the bulkheads, because of structural integrity. What is > recommendable? I'd like light wood, as I plan to change to a clearer > interior. Again, feedback is appreciated! Jeff: WoodenBoat magazine has had a long-running column on the characteristics and uses of various woods. If you know somebody with the back issues on CD, you can find a lot. Some woods are strong and bendable (e.g., white oak, used for wooden boat frames (ribs)) and others are more easily worked and reasonably rot resistant (e.g., mahogany), while others can combine strength and lightness (Sitka spruce, used in boat masts and airplane parts), and others are light and easly worked and rot-resistant (like white cedar, used to plank boats intended to be light). Teak is used extensively now for exterior joinery because the wood is dense, tough, and highly rot resistant. But its oils make it difficult to glue. Red oak has long been avoided because it rots easily and stains easily from exposure to iron. I've seen arguments that it can be used in boatbuilding but that's a minority view. Oak generally does not epoxy up very well, which means it would be harder to secure to the boat by the usual fiberglass tabbing. Bulkheads are often structural members, not just visual breaks, so strength matters. Do get the boatbuilding book or online info from the Gougeon Brothers company. They know all there is to know about epoxy applications in boatbuilding. Chris Campbell >

hi my 2 cents worth okoume ply is great stuff we used it when plywood was called for on all of thecatamarrans that we built however it has gotten extremely expensive. for this reason i might would use fir plywood, a bit heavier and maybe not quite as strong but is ok for bulkheads. also its usually in stock at a good coastal lumber yard i have actually seen it in some home depots. at 1/3 the cost its not a bad deal and it takes paint really well gene ramblin rose cc46 --- On Mon, 9/8/08, ti… [at] ch2m.com <ti… [at] ch2m.com> wrote: From: ti… [at] ch2m.com <ti… [at] ch2m.com> Subject: RE: [Cal_Boats] Bulkheads - OKUME To: Ca… [at] yahoogroups.com Date: Monday, September 8, 2008, 1:15 PM I have used OKUME Plywood in the past. It is Lloyds of London A1 rated, very strong with nicely finished covers.

Good to know there are choices. For a rebuild, of such an important structure, I know that I was willing to spend the few extra bucks for "bulletproof" material. For me the many hours of labor to install wash away the cost, and long term, for me, the Okoume is really beautiful. now we're up to 4 cents? Cheers dEmO From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of gene ulmer Sent: Wednesday, September 10, 2008 5:33 AM To: Ca… [at] yahoogroups.com Subject: RE: [Cal_Boats] Bulkheads - OKUME hi my 2 cents worth okoume ply is great stuff we used it when plywood was called for on all of thecatamarrans that we built however it has gotten extremely expensive. for this reason i might would use fir plywood, a bit heavier and maybe not quite as strong but is ok for bulkheads. also its usually in stock at a good coastal lumber yard i have actually seen it in some home depots. at 1/3 the cost its not a bad deal and it takes paint really well gene ramblin rose cc46 --- On Mon, 9/8/08, ti… [at] ch2m.com <ti… [at] ch2m.com> wrote: From: ti… [at] ch2m.com <ti… [at] ch2m.com> Subject: RE: [Cal_Boats] Bulkheads - OKUME To: Ca… [at] yahoogroups.com Date: Monday, September 8, 2008, 1:15 PM I have used OKUME Plywood in the past. It is Lloyds of London A1 rated, very strong with nicely finished covers.

ti… [at] ch2m.com wrote: > > Good to know there are choices. For a rebuild, of such an important > structure, I know that I was willing to spend the few extra bucks for > "bulletproof" material. For me the many hours of labor to install wash > away the cost, and long term, for me, the Okoume is really beautiful. I built my wood/epoxy sea kayak of okoume plywood over 11 years ago, and it has been afloat in the Great Lakes every month since I launched. Mind you, I maintain it carefully, and the wood is entirely epoxy-encapsulated, so I could have built the boat of birch and it would still be rot free. Okoume is not greatly rot-resistant. I think it falls in the "somewhat" range. The key is to protect it from moisture intrusion by making sure that all edges, surfaces, and penetrations are thoroughly sealed with epoxy. One advantage of okoume is that it's available in marine grades, which means fewer voids in the inner plies. Long ago, "interior plywood" was stuff with water-soluble glues. I understand that all plywoods use waterproof glues now so that's less of an issue. But specs for non-marine grades do allow larger voids. Chris Campbell >

How about Aquatech and Marinetech (I believe I've got that right.) Also mahogany, but not Okoume, and I understand, cheaper. One has no internal voids, the other does. From: Ca… [at] yahoogroups.com on behalf of ti… [at] ch2m.com Sent: Wed 9/10/2008 1:42 PM To: Ca… [at] yahoogroups.com Subject: RE: [Cal_Boats] Bulkheads - OKUME Good to know there are choices. For a rebuild, of such an important structure, I know that I was willing to spend the few extra bucks for "bulletproof" material. For me the many hours of labor to install wash away the cost, and long term, for me, the Okoume is really beautiful. now we're up to 4 cents? Cheers dEmO From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of gene ulmer Sent: Wednesday, September 10, 2008 5:33 AM To: Ca… [at] yahoogroups.com Subject: RE: [Cal_Boats] Bulkheads - OKUME hi my 2 cents worth okoume ply is great stuff we used it when plywood was called for on all of thecatamarrans that we built however it has gotten extremely expensive. for this reason i might would use fir plywood, a bit heavier and maybe not quite as strong but is ok for bulkheads. also its usually in stock at a good coastal lumber yard i have actually seen it in some home depots. at 1/3 the cost its not a bad deal and it takes paint really well gene ramblin rose cc46 --- On Mon, 9/8/08, ti… [at] ch2m.com <ti… [at] ch2m.com> wrote: From: ti… [at] ch2m.com <ti… [at] ch2m.com> Subject: RE: [Cal_Boats] Bulkheads - OKUME To: Ca… [at] yahoogroups.com Date: Monday, September 8, 2008, 1:15 PM I have used OKUME Plywood in the past. It is Lloyds of London A1 rated, very strong with nicely finished covers.