New forum member (equivalents in foam to 9mm marine ply?)

Discussion in 'Boatbuilding' started by Initial_G, Aug 30, 2014.

  1. Initial_G
    Joined: Aug 2014
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    Initial_G Junior Member

    From your answer, I deduce, as meranti is harder and more dense then okoume, that with meranti the boat would be heavier when using the same construction/thickness/panels then it would be when using okoume, but it would be stronger ?
     
  2. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    No, I do not say that. What I'm saying is that you can not guarantee anything and even less to speak of percentage differences .
    If the structure of reinforcement is maintained, with thinner plates meranti (which is stronger), it can achieve an overall structure that may or may not be heavier.
    The designer should calculate the design pressures on the structure which are the same regardless of the material used. Then calculate the required thickness, according to the properties of each material, to withstand these pressures. Therefore, the structure does not have to be neither stronger nor less. In either case it will be just enough to withstand the design pressures (which is always the same).
     
  3. rwatson
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    rwatson Senior Member

    When boatbuilders design plans, they dont specify what type of marine Ply to use.

    Why ?

    Because the mechanical characteristics are not that critical.

    This is why the majority of plywood constructions have a fibreglass layer for the physical properties where plywood could potentially be weak.

    I have never seen the wood variety of plywood being part of a plan requirement.
     
  4. TANSL
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    TANSL Senior Member

    It is possible. You seem to have experience in this type of construction, but do not know if you have it in its calculation. Although I find it strange, I'll believe what you say and I´ll think about the real reasons why designers work as you say.
     
  5. Initial_G
    Joined: Aug 2014
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    Initial_G Junior Member

    Thanks for all the replies

    Another question if I may:
    The plans require a Unidirectional glassfiber 900gr/m² to be used
    Question:
    Anyone have an address (preferably in Europe) where I can get that?
    or:
    Could I use Biaxial 900gr/m² instead
    or:
    Double the layers and use 450gr/m² unidirectional

    thanks
     
  6. whosail
    Joined: Nov 2014
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    whosail Junior Member

    Initial_G I to am a brand new member. My plans are to build a Ruth wherry however I do not no how to post questions. Can you help an old man out?

    whosail
     

  7. Initial_G
    Joined: Aug 2014
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    Initial_G Junior Member

    Hi Whosail

    just go to the main forum page, select the part of the forum u want to post your question in and hit the button "New Thread"
     
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