thin wood+fiberglass?

Discussion in 'Powerboats' started by milfordadkins, Aug 26, 2013.

  1. milfordadkins
    Joined: Aug 2013
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    Location: ashland ky

    milfordadkins Junior Member

    is it possible to construct a hull with one layer of 1/4in then three to four layers of woven fiberglass? will this be a strong enough hull for a 30ft boat? was thinking about this idea for the glen-l 32' cruise missile, just tossing out ideas.
    was leaning toward foam core but want something little easier to assemble, i understand how wood works, never used a foam core before, not sure if it will work with the epoxy i have... and where would i locate the foam at? lowes? home depot? from what i seen on youtube it looked like 1/2 in exterior foam, but i could be wrong any ideas or if anyone is doing the same thing please chime in...
  2. Easy Rider
    Joined: Oct 2009
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    Location: NW Washington State USA

    Easy Rider Senior Member

    I've had similar thoughts.

    I was thinking of building a 26' V bottomed boat in ply (1/4" as you say) and then using a FG overlay that would be about 75% of what would be required for a normal FG hull.

    I had an insight into this by another wild idea. That was to build a typical Ply boat frame and cover it with light cloth. Then glassing the hull and retaining the framework as a sorta non throwaway mold.

    But I soon saw the problem w that in that there would be (as the engineers say) "stress risers". Right by the places where the FG would be attached to a wood frame part there would be a concentrated line of flexing ... too much flexing I'm afraid.

    But w the 1/4" ply on a 30' frame perhaps the flexing would be reduced to a tolerable level. There may be a problem w fairness though depending on how well built the frame was and how many stiffening members there would be (accurately placed) that would prevent the boat from looking like an old steel boat w the traditional "wavy" sides.

    Are you thinking of using full sized framing or lighter weight like the 1/4" ply?

    One would think the resulting boat would be lighter but how could it be as strong or light as just plywood? I don't think it would. But would it be lighter than a regular FG boat? One would think so but the marriage of the two different materials may require more materials to be used to cover up for problems like the flexing I mentioned above resulting in a heavier hull. Heavier than FG may not be good especially for a planing hull. But if it turned out in between the method may have lots of merit. One could build a quick and dirty boat that would be "serviceable" and last "a while" in half the time it would take to build a proper boat w in plywood.

    Another thing to consider is that building the frame may be much more time consuming that sheathing. And the boat you talk about will need to be sheathed twice. Why not just sheath it once w full ply? And if you're worried about bending stiff full sized plywood panels consider double planking (sheathing). I think non-ply planking beats that though.

    I'm totally an amateur so I'll be looking for more knowledgeable posts here.
  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    The Gougeon brothers built hulls like that. They were making multihulls that are long and skinny though.
  4. keysdisease
    Joined: Mar 2006
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    Location: South Florida USA

    keysdisease Senior Member

    There are variations on the male mold method of fiberglass boat building that start with a thin veneer of wood or plywood over the male frame and then you build up your fiberglass from there. One of the nice things about this is if done carefully you end up with a nice wood finish interior.

    The layup schedule should be the same as without wood.

    And Milford, you need to hook up with a supplier of boat building supplies. Start with Defenders The foam core fiberglass boats are made of in not at Lowes or Homies.

  5. milfordadkins
    Joined: Aug 2013
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    Location: ashland ky

    milfordadkins Junior Member

    was planning on using full frames, and three layers of 3mm then epoxy and fiberglass. on my bandido, but might try to convert my 32' cruisemissile plans to wood construction...
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