Plywood

[ted655]

Untill it gets wet. Then it's a high tech sponge.

[Raggi_Thor]

Do you have any prices for that composite?
If marine plywod is too expensive, I suppose composites are more expensive.

I pay for example 10$ for low cost plywood, 20$ for marine grade Okoume plywood, and 40@ for divinycell foam. The foam then need 2x450g of bidirectional glass and the same weight of epoxy. The glass and epoxy (close to 2kg) costs another 20$...

[kach22i]

Originally Posted by ted655

Untill it gets wet. Then it's a high tech sponge.

I think it's a closed cell foam, will not absorb water. It's mostly fiberglass, that's not known for absorbing water is it?

Lots of information (2 pages so far) has been posted in another forum which I post in, pricing to. Should be the same price or close to the same price as marine plywood, and you don't have to seal it.

Link:
http://www.hoverclubofamerica.org/fo...?showtopic=883

You can always e-mail them for techincal data and prices.

http://www.coosacomposites.com/

I found out about this product at boatdesign.net, you may of heard of it.

[SmithCraft64]

I went to the local lumber yard today and priced a single piece of 1\2 inch 4x8marine plywood. I was a bit surprised by the $80.00 price tag. Is this the going rate for marine plywood? Needless to say im going to shop more. I will check out the links listed in the posts above also. I live in the State of California in the U.S. Out of pure unadulterated curiosity what are the prices in your areas? Marine grade 1\2, 5\8, 3\4 4x8 sheets. Thank you in advance.

[timgoz]

It has been 8 years ago since I bought some. One-half inch (4 x 8) went for $50 a sheet. It was not the top of the line stuff as it was for a lofting floor. I was then going to utilize it for the interior.

Marine ply comes in many grades with differing ply counts, wood types, ect... Do a little surfing and you will get a better idea of what you need to meet your needs.

TGoz

[SmithCraft64]

This plywood was 5 ply 1/2" 4x8 FIR Marine grade AB. I noticed it seemed dry and brittle. Does this type of plywood have a shelf life? At least to a point and depending on how long it has been stored I would imagine. This was inside there barn stacked flat. It was the last piece they had in stock. What kind of things should a boat building rookie look for in marine plywood? I have completely taken my SmithCraft down to the aluminum hull. I am replacing every bit of wood in her. I am going to replace alot of the wood bracing with aluminum gussets to lighten it up as much as possible. I'll post some pictures or maybe a link to some soon. It would probably be best to link to them. That way yawl can take a look at my latest adventure my second restoration. And a Question for the moderator. This started as a post on plywood . Should I move it somewhere else in the forums? From this post on? Let me know and I'll do just that.
thanks SmithCraft64

[ted655]

Closed cell polyurethane foam is fine as long as it is not put in a situation where it migt be subjected to "constant" moisture. That would be anything below the waterline or in a bilge situation. In a perfect world (the one on paper), fiberglass is impervious to water. Then there is the real world, with all it's stress cracks, delamination, blisters, groundings, & leaks around thruhulls, screws, bolts, shaft logs, etc..

[Raggi_Thor]

Originally Posted by SmithCraft64

...FIR Marine grade AB. I noticed it seemed dry and brittle. Does this type of plywood have a shelf life? ...

I think fir as pine will always cheek when the plywood dries.
It's a common problem.
That's one reason to use Okoume or Meranti.
For 6mm (1/4 inch) I pay 60USD per sheet (4x8 feet) of Okoume.
Then transportation may be almost the same if I buy just a few sheets.

[kach22i]

Originally Posted by ted655

Closed cell polyurethane foam is fine as long as it is not put in a situation where it migt be subjected to "constant" moisture. That would be anything below the waterline or in a bilge situation. In a perfect world (the one on paper), fiberglass is impervious to water. Then there is the real world, with all it's stress cracks, delamination, blisters, groundings, & leaks around thruhulls, screws, bolts, shaft logs, etc..

Well stated.

[SmithCraft64]

Thank you all for your input. Im off shopping for the materials mentioned. Have a good one. SmithCraft64