Material masses and reccomendations.

Discussion in 'Boat Design' started by Jet FiSH, Apr 3, 2008.

  1. Jet FiSH
    Joined: Mar 2008
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    Jet FiSH Junior Member

    Looking for the masses of materials for the displcement calc's.
    i.e. mass of 1mm ply per meter squared
    mass of fiberglass per meter squared per mm
    solid foam mass per meter cubed

    also what would you guys reccomend for a hard chine in a single chined v planing hull? (small) something like H3.2 treated 25x50 (1X2) ??haha

    also how do you bend plywood and mold it? do you steam it then screw it in place, i.e. for a femal plug?

    many thanks :D
    FiSH
     
  2. rwatson
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    rwatson Senior Member

    Thats a bit unrealisic - what type of plywood? what type of foam ? if you know what material you are using, the manufacturers will give you the weight.
    You dont even provide the size fo the boat with the single chine. Are you over 18?
    Hey - one litre of water = 1 kilo, unless its sea water then ....
     
  3. Omeron
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    Omeron Senior Member

    What you are looking for is the specific gravity of marerials.
    If it is a composite, find out what pecentage of what has gone into it, then do the math...
     
  4. kach22i
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    kach22i Architect

  5. Landlubber
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    Landlubber Senior Member

    Foam is sold as being, say 750, which is in fact its weight.
     
  6. Jet FiSH
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    Jet FiSH Junior Member

    deck length approx 2m at this stage.
    lwl unknown at this stage
    12 degree deadrise at transom
    20 degree deadrise at midships
    330mm freeboard at midships
    420mm max beam at midships and same at transom

    yeh ok i guess it was a pretty vague question.

    yeh im 17, why?
     
  7. tom28571
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    tom28571 Senior Member

    Here are the numbers I use from my own measurements.

    Occume plywood =.102lbs/mm/ft^2 = 1.098lbs/mm/m^2

    meranti plywood = .126lbs/mm/ft^2 = 1.356lbs/mm/m^2

    keroung plywood = .144lbs/mm/ft^2 = 1.55lbs/mm/m^2

    The keroung may be something else, which is anybody's guess.

    There are other plywoods that have various number of plies and various woods used for inner plies so some weights may fall between these figures. Some Chinese plywood I have run into lately is all over the map. I have recently even seen some plywood supposedly rated as marine that had metal staples hidden inside. I speculate that these are used to connect the edges of interior flitches instead of using gluing edge-banders like they should. The staples look just like the office desk type and are likely a way to use cheap labor instead of machines.

    I ran some boil and soak testing on the heavy stuff. The glue passed the tests just fine. After a day in the water, it absorbed enough to sink to the bottom. Not what I want in my boat.
     
  8. Jet FiSH
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    Jet FiSH Junior Member

    awesome, cheers man!
    and how do you mould the ply?
     
  9. Pericles
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    Pericles Senior Member

  10. Jet FiSH
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    Jet FiSH Junior Member

    Thats premo man!:D
    fantastic
     

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