What do you think would last longer?

Discussion in 'Boatbuilding' started by mariobrothers88, Jun 26, 2021.


What do you think would last longer as a bulkhead?

  1. Interior grade Birch plywood 1/2" properly encapsulated in 10oz fiberglass and epoxy

    2 vote(s)
  2. Marine grade plywood 3/4" made by consmos (Chinese manufacturer) with no fiberglass or epoxy

    0 vote(s)
  1. mariobrothers88
    Joined: Sep 2020
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    mariobrothers88 Senior Member

    Just curious to see everyone's response!
  2. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    I presume that this is in relation to the 40' x 20' houseboat that you are planning to build?

    Re the above two choices on offer, can we assume that the strength of both bulkheads (eg re buckling) are the same?

    Re if one would last longer than the other - it is the age old answer "it depends....." on so many different factors.

    Edit - are you still building the Woods Flica catamaran mentioned in this thread?
    Ways to transport hull of catamaran https://www.boatdesign.net/threads/ways-to-transport-hull-of-catamaran.65607/
  3. mariobrothers88
    Joined: Sep 2020
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    mariobrothers88 Senior Member

    Thanks for the reply Baja sailor. Yes still building the flica I am just planning out my next project after that one :)

    Yes let's just assume the same strength in this scenario and yes it would be for the 40'x20' houseboat.

    The marine ply is made by consmos a Chinese manufacturer does anyone know anything about the quality of consmos?
  4. kapnD
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    kapnD Senior Member

  5. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    Don't even bother giving the birch option a second thought, it's not something that should be anywhere near water.

    A known Marine plywood and epoxy is your best option, an unproven marine ply is better than birch.

    Your best option is to wait until the supplies of all types of wood improves. Why spend that much time and money on questionable materials that make up a major component of your project.
  6. fallguy
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    fallguy Senior Member

    100% agree

  7. sdowney717
    Joined: Nov 2010
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    sdowney717 Senior Member

    Interior grade birch, A few pieces I had from old kitchen cabinets, the glue for the layers was not waterproof, it fell apart, splitting open along edges.
    And I had smeared epoxy on all the cut edges. Moisture got into the panel anyway.

    I did salvage the panel, but it was a lot of work. Had to mechanically wedge open the layers on the edges and put in glue like tightbond2 then clamp it. It kept cracking open edges for a while but now it is ok. The only reason I fixed panel, it was nice and flat, I had used it for a cabinet door on the flybridge. Plywood like that tends to self destruct outside.
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