I want to replace a couple of bulkheads on my boat. Some of the ones that are in it, are rotten, where they are up against the hull, rather than try to repair them, or just leave them, i want to take them out, and use them as a template to make new ones. What i want to know, is do you have to use marine plywood, or can you use any other type. I did once repair a marine ply dinghy, I used marine ply to do that, as it was a dinghy and the repair was to the bottom of the boat. The marine ply, was pretty expensive, and i had to order it and wait about a week, which is why i just want to use ordinary ply, is this possible.
Marine ply
- Thread starter AtlanticAl
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bulkheads
Marine ply is a must Bulkheads are strategically placed by the designer and play ian important
role in the structural integrity of the boat. They must be sized properly and glassed in and tabbed in exactly where they were before
Marine ply is a must Bulkheads are strategically placed by the designer and play ian important
role in the structural integrity of the boat. They must be sized properly and glassed in and tabbed in exactly where they were before
Marine ply is for applications that are CONSTANTLY immersed.
Exterior PRIME grade of ply (with least amount of defects) will be suitable. The emphasis is on GOOD plywood not the 'crap' one buys in a 'box store' ... a REAL lumber yard frequented by 'tradesmen'.
If you want 'good looking, etc.' then consider to buy 'one side good' or "two side good" (pre-sanded) and then apply finish as desired ...... OR to apply a good quality veneer over the base pre-sanded plywood if you want hoi-poloy.
Exterior PRIME grade of ply (with least amount of defects) will be suitable. The emphasis is on GOOD plywood not the 'crap' one buys in a 'box store' ... a REAL lumber yard frequented by 'tradesmen'.
If you want 'good looking, etc.' then consider to buy 'one side good' or "two side good" (pre-sanded) and then apply finish as desired ...... OR to apply a good quality veneer over the base pre-sanded plywood if you want hoi-poloy.
I have bought and used 12mm thick Teak Marine Plywood. I got it from Boulter Plywood in Somerville, MA, 02145. Ph. 888-9LUMBER I only had to get a Quarter sheet to do my job. That was about $50. A full sheet will be in the neighborhood of $200. they are on the web at boulterplywood.com. Tey carry lots of marine woods. I don't know where Grand Lake is, but it's probably no where near MA.
Al - i just spent most of the late summer and early fall replacing both bulkheads on my 81 Catalina 27. I purchased marine grade plywood from a place here locally that was recommended to me by others. Boulter is certainly and option, I have used them before as well, but shipping costs are not cheap. If you can find marine grade(and I would not recommend anything but) from a local place, or even a good lumberyard that is near you may be able to order it for you. There is also a product called Okume marine grade, which is similar to teak, but less expensive. I have used that product as well, using a Red Oak stain, and Cetol Marine, and I cannot tell the difference between that and my original teak. I have some pictures if you want me to send some to you. I followed the same path you are thinking, carefully remove the existing ones so that you have something for a template. I actually bought a cheap piece of 1/2" plywood, traced the old ones onto the plywood, dry fit them, and made some minor adjustments, and when that was done, I simply clamped them to the top of the marine plywood, and using a router and a really good top-collar straight cutter, cut the new one. They fit better than the old ones did, and if I ever need to replace them, I have the templates already.
I coated all edges in glass, then 3 coats of cetol marine, and 3 coats of gloss. Feel free to email directly and I will be glad to answer any additional questions.
I coated all edges in glass, then 3 coats of cetol marine, and 3 coats of gloss. Feel free to email directly and I will be glad to answer any additional questions.
A possible option that is available in just about any city is form ply, used for concrete forms. It's void free and uses waterproof glue. It is very close to a marine grade ply with a final laminate on one face that's 'slick' so the concrete won't be imprinted with a wood grain or stick that needs to be sanded off to tab in.
It's not cheap, only slightly cheaper than marine grade, but nearly any decent lumberyard has it. (Heck even Home Depot and Menards carry it in my town)
It's not cheap, only slightly cheaper than marine grade, but nearly any decent lumberyard has it. (Heck even Home Depot and Menards carry it in my town)
I've replace the entire interior on three different boats. For internal wood use a good piece of exterior grade plywood. Go some place that does not mind you picking through the pieces. Look at the edges and try to find a piece with no voids in the ends. If you want it to look nice stain it or cover it with a piece of linoleum once you have it cut out. You can find something with nice nautical theme.
Yes, exterior grade plywood uses waterproof glue. But true marine ply like Joubert, Hydro-Tek, or Aqua-Tek has more plies usually and no voids. For bulkheads I would use one of the three. The Hydro-Tek is 13 plies for 3/4".
Thanks for all the usefull advice. I was leaning towards marine ply, for the main reason that it would match what is already there, but had decided, i am just going to use exterior, and stain it. The main reason is, it so hard to get marine ply where i am, without paying a big delivery charge, plus, these bulkheads are in no way structural. The fiberglass bulkheads come up some a third of the way, one at least half of the way, then the ply bulkhead continues up to the deck head, they are not glassed in, i can get my fingers between them and the deckhead, and they dont touch the sides of the boat. They are more really like dividers, so you cant see someone on the toilet, or so your pillow dosent get soaked from galley sink. Also as a need a couple of sheets, that could be 400 bucks, when i can get a couple of sheets of quality exterior for a third to a quarter of that.
If it just a divider bulkhead this might work for you? http://www.lowes.com/pd_8566-21553-...URL=/pl__0__s?Ntt=fiberglass&page=3&facetInfo=.
I saw this at a local store during the summer and have been trying to come up with a boat related use for it. Maybe make a nice headliner.
That stuff is nice but it must have some backing. If this bulkhead serves only as a partition then using 1/2 inch and laminating with something fancy is also a posibility. You can also but MDO plywood which is used for outdoor signs and is completely smooth with no grain but is very paintable. The problem with most plywood is the one side is much better that the other.
I would like to offer some information on plywood since I discovered the differences quite by accident. No, and I'll say it again, No exterior grade plywood is available that meets any certification as Marine. Marine plywood has negligible or non existant voids in the core. It also has water boiled proof glue used in it's lamination. The cores must be hardwood and not softwood as in exterior grades. There are two standards for marine certification. ASTM and BS1088. I found this out quite by accident after purchasing Marine Teak at 200.00 per sheet. It turns out the core was Kapok which is nothing more than cork. After replacing my bulkheads I purchased an additional sheet to keep the look the same only to discover the number of plys was different. Upon searching the manufacturers website a new post had been made a few weeks earlier touting this as 'Marine Decorative Plywood Not For Structural Applications'. I had the distinct pleasure of tearing 800.00 worth of junk out and purchasing Joubert Okoume complete with the Lloyds Register sticker. Be sure to look over the entire application. Some of these boats rely on a grid of interconnected woodwork to add stiffness and structural strength. Will exterior plywood work? It might. What is your level of risk tolerance? Just thought you might like to know.
Good point Ross. The FG panel is thin enough that falling into it or striking it with a sharp corner would probably break it.
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