Floor material besides wood

Discussion in 'Materials' started by gabedance, Mar 27, 2007.

  1. gabedance
    Joined: Mar 2007
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    Location: Plant City, FL

    gabedance New Member

    I have a 91 Ski Brendella (Just like a Ski nautique or Mastercraft). My stringers were bad so I replaced with Seacast. Now I am puting the floor back in. I went with the seacast because I didn't want to replace wood stringers in 10-15 years again. I would like to use some other material besides wood for the floor for the same reason. The floor basically rest on one side on top of the stringer and just sits on top of the floatation foam in the cavity between the hull and bottom of floor. The wood floor was 3/4" thick. I was reading on some topic about coosa board (www.coosacomposites.com ) Is this stuff good and how much per 4'x8' sheet 3/4" thick? What about some of the new plastic lumber I see advertised around? The floor is covered in carpet so looks are not important and I will still fiberglass over top of the floor from the sides of the boat to the stringers just as was done over the wood. Any other help, ideas for materials will be appreciated.
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Seacast is a core material, not a structural material. It works solely by having it in a sandwich construction and it is the only way it works. You can't replace wooden structural members with it, without making these pieces (stringers in your case) using a sandwich method of sufficient skin thickness.

    The same is similar of your sole (your interior floor) which is plywood. The plywood is a structural aspect of the hull. It's bonded to the stringer (most of the time), to the hull sides and to bulkheads or other athwartship divisions within the boat. Pound for pound plywood is stronger then steel (believe it or not) and is the prime reason it is used so much. So if you replace the plywood (a structural element) it should be replaced with something with sufficient qualities to withstand the loading.

    I've heard good things about Cossa panels, but have yet to use any, so I can't speak about this product. Their web site leaves a little to be desired as far as information, pricing and availability. Maybe someone who has used this stuff will chime in.
  3. fiberglass jack
    Joined: Dec 2005
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    Location: toronto

    fiberglass jack Senior Member

    cossa is great stuff takes a bit of getting use to the itch, nasty worse case of itching wear a tyvek
  4. Bentwood
    Joined: Mar 2006
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    Location: Durham, NC

    Bentwood Bentwood

    I am using coosa bluewater-26 to substitute for plywood in sole, berth, and bulkhead applications. I am also thinking of using it to substitute for 2 layers of 1/4" plywood on the deck. I agree that the website is not very informative, but I have called their techinical support and gotten good advice. The product works well with carbide tipped wood working tools, and grinds easily with coarse abrasives. I am using epoxy to attach the coosa to wood and fiberglass. The dust is nasty. I have been relying on cotton gloves, dust collection, and dust masks to control the exposure.
  5. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    A product that looks like masonite, but is used for industrial food prep cutting boards withstand immersion without warpage or absorbtion. On 10 yr old sandwich units (the thing you see in pizza places where they make sandwiches), these boards were always in perfect condition----- I had a company that specialized in restaurant equipment rebuilding.
    So when time came to redo my galley counter, I ordered a sheet. I also used a piece for my anchor chain wear plate and a few other things.
    The stuff is absolutely indestructable. Never warps, wears like iron, takes heat, water, dropped anchors, etc..
    I actually thought at one time I'd make a killing on the marine market with the stuff----- nobody had thought of the idea yet.
    So how to get it, and what to expect? It comes in all thicknesses, including 3/4", it is expensive, and it begins life a light brown, but gets darker unevenly. I liked it because it darkened like wood does, actually developing a patina. It could be painted, of course. It's strong in compression, and weaker tensily, though very strong in tension. I doubt it would sag like plastics do. It's made of wood and resin.
    How to find out more? Look online for cutting board materials, industrial or commercial. I no longer have a line on it. A 1/4" sheet 5 years ago cost a total of about $190.00 shipped (the shipping was a lot).

  6. alan white
    Joined: Mar 2007
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    Location: maine

    alan white Senior Member

    I found it.


    This stuff could find a place on any boat. Great for protecting areas around anchors (I glued it with polyurethane caulking compound), backing plates for hardware, step-aboard footplates (to replace teak), screw-on inspection covers, any place where abrasion is likely to scratch nice surfaces, and of course, cutting boards. I would suggest anyone buy a small cutting board and try it out in the worst conditions they can think of.

  7. joefaber
    Joined: Sep 2005
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    Location: san francisco

    joefaber Junior Member

    i've been 'noodling' building a housboat for a while. in my research,
    i found this site: http://www.lockdry.com/features.htm
    which may answer your need for altenate decking material that is simple to install. http://www.lockdry.com/lockdrydemo.htm
    tested to 240psf live load, weighs about 1# per sqft (i weighed a sample on a certified scale),
    6" board width, 12' to 30' lengths, made of 6005-T5 Aluminum
    costs $7us per square foot as of Feb 2005 and comes in four colors.
  8. RingLeader
    Joined: Feb 2007
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    Location: Slidell, LA

    RingLeader Junior Member

    You don't really need the Bluewater 26 Coosa for a deck. Their 15 lb density board is just fine. I re-cored a 11' x 4' hatch in my deck with 1/2" 15lb coosa. Its stronger and lighter than the 3/4" plywood core that was there before. The Bluewater 26 is best for transoms.

    Its hard to beat Coosa, but for decks I really prefer NIDA core. Also very easy to use and not quite as costly as Coosa.
  9. catman021
    Joined: Jun 2007
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    Location: Philadelphia,pa

    catman021 Junior Member

    With the NIDA core, what's it's cost for a 4x8 sheet? I'm following your idea of using it for the decking instead of plywood but how's its strength, speaking in terms of installing either pedestal seats or maybe going with back to backs?

  10. RingLeader
    Joined: Feb 2007
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    Location: Slidell, LA

    RingLeader Junior Member

    A 4x8 of 16mm NIDA (~5/8" thick) runs about $55 from FGCI. http://www.fgci.com The big hit is in the shipping. Its best to find someone local to you so you don't have to pay $90 to freight the stuff to your door. As for putting in pedistals... You can glass 1/2" plywood backers to the underside of the NIDA deck section before you install the deck. That will hold the screws just fine.
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