Is it more buoyant ?

Discussion in 'Stability' started by matt flyfisher, Apr 13, 2012.

  1. matt flyfisher
    Joined: Aug 2010
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    Location: tasmania, australia

    matt flyfisher Junior Member

    HI,
    Can Any One Help With An Issue I Have, I Am Putting Outriggers On A Canoe And Am Using Pvc Down Pipe And Was Wondering If The Pipe Was
    1 Empty And Sealed OR
    2 Filled With Foam And Sealed.
    Which Would Take The Most Weight To Sink The Pipe ?

    CHEERS MATT
     
  2. Submarine Tom

    Submarine Tom Previous Member

    Number one because the air in the pipe would weigh less than the foam in the same pipe.

    Number three, a vacuum in the pipe would be the most buoyant of all.
     
  3. Petros
    Joined: Oct 2007
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    Petros Senior Member

    The less the finished assembly weights the more buoyant it would be, so the empty tube.

    However, PVC pipe is not very strong, and prone to buckling. If it was filled with foam it would have more strength since it would resist bucking better. A much stronger and actually less costly way to go is make some light box beams out of plywood.
     
  4. matt flyfisher
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    matt flyfisher Junior Member

    [​IMG]
    i was going to wrap a light coat of glass over the top
     
  5. johnben
    Joined: Apr 2012
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    johnben New Member

    For the small increase in weight I would fill it with foam, not only will it become less flexible, if punctured or cracked it will always retain positive buoyancy.
    John
     
  6. Petros
    Joined: Oct 2007
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    Petros Senior Member

    If you are going to wrap them with glass why not leave out the pipe? A Square beam is structurally more efficient (stronger in bending for the same weight). Or are just using them as a mold?
     

  7. matt flyfisher
    Joined: Aug 2010
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    Location: tasmania, australia

    matt flyfisher Junior Member

    hi
    yes petros very true, i could have built ply ones myself.

    i will stick with what i have made so far, there quick to knock up! a coat of glass and some paint and call them attempt 1.
    i will test the shape, and build new ones or mold them.
    there going on a 4.2M canoe i got a new 3hp yam for it
     
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