Trying to figure out how to design Jon boat

Discussion in 'Boat Design' started by eagle19, Apr 6, 2014.

  1. eagle19
    Joined: Apr 2014
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    Location: Texas

    eagle19 Junior Member

    Well I've been looking at plans from Uncle John and it looks like I'll only need 5-6 pieces of ply so it should cost me $120 at most for 6 pieces of 1/4 inch. I should have enough money for epoxy, and fiberglass joints, and maybe fiberglass the bottom!
  2. johnhazel
    Joined: Jun 2008
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    Location: Michigan

    johnhazel Senior Member

    For the strength, low weight, and low cost, take a look at style 7781 9.0oz/yrd^2 fiberglass.

    It is thin and does not need as much resin as some other types.
    That reduces weight and cost.
  3. messabout
    Joined: Jan 2006
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    messabout Senior Member

    Dcockey, Compression/bending. Yours is a legitimate question.

    Consider the direction of the force acting on the panel. If the force is perpendicular to the panel, then my simplistic assumption does not apply. If the direction of force is more nearly vertical, as in slamming, the vectors suggest a difference. I hasten to agree that the forces are never purely vertical, they are distributed.........except when running aground.

    I should not have mentioned such an argueable technical matter. My bad.

  4. DCockey
    Joined: Oct 2009
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    DCockey Senior Member

    Pressure always acts normal on a surface. Shear stress due to viscosity is tangential to a surface. Pressure due to slamming acts normal to the hull surface, but will generally be less the more vertical the surface is.
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