16' Runabout out of PLEXIGLASS?

Discussion in 'Materials' started by smattiso, Jun 19, 2020.

  1. smattiso
    Joined: Jun 2020
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    smattiso New Member

    I am investigating the possibility of building an entirely Plexiglass hull. Am I crazy? From my talks with suppliers and researching the spec sheets this seems entirely possible. Convince me that I'm an idiot, I usually am.

    FYI: Triton subs builds submarine bathyspheres out of Plexi and they go very deep, so this material is certainly strong enough. What am I missing? Corrosion? UV exposure? Shearing forces? etc.
  2. Barry
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    Barry Senior Member

  3. kapnD
    Joined: Jan 2003
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    kapnD Senior Member

    What building process do you have in mind?
    Simple designs that can be done in plywood might work out, but making joints will be interesting.
    Thermowelding comes to mind, but like metals, plastics cam become brittle when overheated.
    I can envision a whole boat built of clear acrylic and superglued together looking cool.
  4. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    is plexiglass always clear ? Maybe you are "clearly" out of your mind ! :eek:
  5. gonzo
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    gonzo Senior Member

    It is clear for a while. The material will yellow and craze with age. Also, any scratches will show, which will require a lot of care while operating so it doesn't rub against anything.
  6. KeithO
    Joined: Jul 2019
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    KeithO Senior Member

    Perhaps you could blow mold the hull the way people do airplane canopies ? No joins would be a big advantage. For me, plexiglass is just too inclined to shatter, using polycarbonate one would lose out on the optical characteristics but it would be considerably tougher and scratches could be polished out.
  7. Dejay
    Joined: Mar 2018
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    Dejay Senior Newbie

    Cool idea!

    You'd probably want to research acrylic (plexiglas), polycarbonate (lexan) and PETG glass. I've read that acrylic has best UV resistance but can shatter. Maybe that is better than being more elastic like polycarbonate.

    Thermoforming might be the best solution. Or maybe just doing the floor or part of the floor with glass, so the hull sides are wood or fiberglass. You might even see more with a bit of shade from the sun. You might have to polish or recoat the acrylic from time to time, like you can do with car headlights.

    I've had this idea of a big tube you could lower into the water from a boat, so you'd have a kind of reading nook underwater.

  8. gonzo
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    gonzo Senior Member

    Polycarbonate is too soft to be polished. Acrylic (plexyglass) can be sanded and polished.
    Dejay likes this.
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