Composite Rowboat

Discussion in 'Fiberglass and Composite Boat Building' started by Scott M.., Oct 13, 2020.

  1. TANSL
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    TANSL Senior Member

    I thought that a certain material was fragile or not by itself, by its own nature, not by the construction system used with it. I'm wrong?.
    Could the opposite be true, that a fragile material, with a certain type of construction used, ceased to be so?
     
  2. Rumars
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    Rumars Senior Member

    The problem with the design as it stands is that it will be a terrible row boat. About the same as a flat bottom inflatable I would say. I understand you want a stable even platform for fishing but you should understand the compromise you are making. Rowboats don't drag immersed transoms and are not almost rockerless. If I had your SOR I would probably build a catamaran.
     
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  3. DCockey
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    DCockey Senior Member

    I do not know of a technical definition of "fragile". A common definition is "easily damaged or broken".

    Is wood a fragile material? Consider a chair made from wood. If the parts of the chair are very thin and the joints are not well designed then the chair may be fragile. If the parts are thicker and the joints are well designed then chair will not be fragile.
     
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  4. Scott M..
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    Scott M.. Junior Member

    I have been doing some more thinking about this project and I think for purposes of wanting to travel a road no one has done before and the overall cost and time of composite fabrication that I am going to use LineX.

    Super strong, sprayable, impact resistant, cheaper, faster construction and pretty light.

    I thank everyone for all their help and I will post my progress and completed construction.
    Thanks
    Scott
     
  5. bajansailor
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    bajansailor Marine Surveyor

    I had to ask Google what LineX is -
    Home | LINE-X https://linex.com/

    I am a bit puzzled though by your assertion - "Super strong, sprayable, impact resistant, cheaper, faster construction and pretty light."

    What are you planning on building the boat with, before you spray it with LineX?

    Be aware that it will still be a terrible rowboat (as Rumars noted above) if you build it as per your proposal outlined above.
     
  6. BlueBell
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    BlueBell . . . _ _ _ . . . _ _ _

    Skin on Frame fragile?
    Ridiculous.
     
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  7. srimes
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    srimes Senior Member

    Skin of frame is relatively weak when it comes to puncture/cut resistance, and abrasion. It excels in impact resistance. Carbon fiber is brittle and has relatively poor impact resistance.
     
  8. TANSL
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    TANSL Senior Member

    @DCockey, this is what I found on the internet:
    "Brittle Materials : Brittleness is the ability of certain materials to fracture or break into smaller pieces, suffering little or no deformation. It is the opposite of toughness and is a property of substances whose response to stress or tension leads to appearance of cracks inside. "
    That is the concept of fragility that I am thinking about. Do you now understand why my previous post?
     
  9. BlueBell
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    BlueBell . . . _ _ _ . . . _ _ _

    What a load of rubbish.
    You have obviously never seen a quality SOF.
     
  10. Scott M..
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    Scott M.. Junior Member

    What you mostly see on line when looking up LineX is a coating placed over things for various purposes. Most well known is as a sprayed in truck bed liner. But it has been used for pool spray in liners, flat roof application and even used overseas on the outside of buildings for bomb suppression.

    It can also be a stand alone material as well depending how thick you make it.

    I have done some fairly extensive practical testing for my job in the aerospace industry and a layer of approximately .100 thick is virtually bulletproof and is comparable in weight with multi-layer composite.

    As far as the boat shape, my main goal was to create a optimally stable boat for fishing and porting camping gear. Rowing of the boat is secondary and should be better than your traditional flat botton blunt front Jon boat just based on its weight reduction and tapered front which will cut through the water much better.

    For the most part the boat will be operated with a 36lb. Trolling motor 75% of the time, a 5hp outboard 15%, and 10% rowing.
    Scott
     
  11. DCockey
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    DCockey Senior Member

    Brittle and fragile are two different words in English with similar but different meanings. Brittle is usually used to describe a material. Fragile is usually used to describe an object.

    An object can be made from a brittle material but not be fragile. Glass is brittle. A round solid sphere made from glass would usually not be considered to be fragile.

    Soft aluminum is the opposite of brittle. It will deform a large amount before fracturing. But a frame built from small tubes of soft aluminum could be considered to be fragile.
     
  12. DCockey
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    DCockey Senior Member

    Scott, what would provide stiffness if the hull is made of LineX?
     
  13. TANSL
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    TANSL Senior Member

    @DCockey, it seems to me that I have already explained what I understood by "fragility" (see post # 38). I think it is clear enough for the good understanding. If you want to understand it, well, if not, I am not going to insist or argue with you about the nuances of a language that is not mine.
    Let's see a better definition of fragile than I could give: fragile https://www.thefreedictionary.com/fragile
     
    Last edited: Oct 16, 2020
  14. Scott M..
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    Scott M.. Junior Member

    I would rather not go into details but let's just say you have the same stiffness issues across broad spans similar to composites.
     

  15. gonzo
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    gonzo Senior Member

    A skin on frame has a skin of fabric or a polymer laminate that is relatively easy to puncture. A boat carrying 1000 lbs hitting a rock will generate a lot of force, concentrated on a small area.
     
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