core for cockpit floor ??

Discussion in 'Fiberglass and Composite Boat Building' started by marlin974, Nov 23, 2013.

  1. boatbuilder41
    Joined: Feb 2013
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    Location: panama city florida

    boatbuilder41 Senior Member

    I guess my posted pic doesn't show what you were asking about. I apoligize for that . But my deck material is the same as my stiffeners. It is solid fiberglass sheets 1/4 inch thick. Although it seems to have a little flex. It is minimized by the structural grid created by the same fiberglass panels.
     
  2. upchurchmr
    Joined: Feb 2011
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    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    boatbuilder,

    The reason for core is to save weight for the same structure.
    If you have solid fiberglass you might as well make it aluminum

    Core is more difficult to do well. Lots of people do it poorly.

    Piles of solid fiberglass is another way to make a boat poorly, IMO. Cheers.
     
  3. marlin974
    Joined: May 2013
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    Location: france

    marlin974 Junior Member

    sandwich allows the use of larger panels, stiffeners use less, gives more rigidity than a single skin,Sometimes weight savings
    as well, requires good implementation and sizing

    I have rarely seen decks, with single skin, (walking area)
    generally, there is at least some plywood,
    In the same way, I do not think this is prohibited to use single skin,
    as long as your structure/laminate is properly sized, I do not think it could have any problem
     
  4. jiggerpro
    Joined: Sep 2007
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    Location: spain

    jiggerpro Senior Member

    Corecell M made by Gurit Sp system, IMO the very best check it
     
  5. FishStretcher
    Joined: Oct 2011
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    Location: On the Water

    FishStretcher Junior Member

    The floors in my 7.6 meter /25 foot boat came with 1/2 inch/13mm end grain balsa. The puncture resistance was an asymmetric fiberglass schedule, perhaps 2.5x to 3x the thickness topsides as below. In polyester, it was nearly 0.300" (7.5mm) topside, including a healthy gelcoat layer. Perhaps 1.6-2.2mm on the bottom.

    Foam the density of balsa lacks the equivalent shear modulus and compression strength. (200 kg/m^3). Rather than try to duplicate that, try divinycel H80 in 13mm or 1/2" thickness with adequate topside glass to prevent damage from penetrating injury. Or another foam in the 80+ kg/cubic meter density. This is a guess. But I repaired this deck where it had balsa decay with H80 and vinylester.

    End grain balsa is nice in that the grain keeps water migration damage to a minimum, unlike plywood. I don't care for it much, as it decays. So I prefer foams. But for decks end grain balsa is MUCH MUCH better than plywood, which has transverse grain and much higher density. Both of which are disadvantages.
     

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    Last edited: Dec 16, 2013
  6. marlin974
    Joined: May 2013
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    Location: france

    marlin974 Junior Member

    yes it is a good solution,
    find a relationship between the outer skin and the density of the foam.

    the better now I think would be make some homemade tests,
    on samples and compare.

    the real marine plywood (sapele, moabi) is better than balsa
    (mechanical properties and resistance to moisture)

    as you say, both have their disadvantage / advantage
     

  7. CEShawn
    Joined: Dec 2013
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    Location: United States

    CEShawn New Member

    I've heard rumors that Nidacore is no longer being made. 3M purchased the company and is going to stop making it. Not sure if that is true.

    I have seen Plascore and its prices. Has anyone actually used the product themselves and anything to say on it?
     
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