Self Repairing Hulls?

Discussion in 'Boat Design' started by STRIDE, Jun 23, 2010.

  1. STRIDE
    Joined: Jun 2010
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    STRIDE Junior Member

    I have seen "Self Repairing" composite structures using a material called shape memory polymers.

    These materials have large strain capability and the ability to return to their original shape when they are heated. So, theoretically, after a serious impact, you could just heat your hull, and restore it to it's original shape. The shape memory polymer resin can be used to create a composite like any other thermoset resin.

    Does anyone have any experience with this material?
    Or maybe a source for Shape Memory Polymer resin?
     
  2. apex1

    apex1 Guest

    That is a joke right?

    How would a thermoplast stand the loads of a boat? Except maybe a dhingy or canoe.

    Regards
    Richard
     
  3. Paul B

    Paul B Previous Member

    He said thermoset, not thermoplastic.

    Regardless, I doubt there is any real application here. If it was easy the auto manufacturers would be making body panels that would simply pop back into shape with the application of a bit of heat after a fender bender.
     
  4. apex1

    apex1 Guest

    And then? It is a thermoplast by nature.;)
    And I understood what he said............

    The auto industry btw uses it in exactly the way you describe! For bumper fenders!
     
  5. STRIDE
    Joined: Jun 2010
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    STRIDE Junior Member

    ...

    No joke, Richard.

    Veriflex is the only distributed shape memory resin system that I could find in the US. The Ultimate Tensile Strength of the neat resin [Veriflex E2] is around 11,000 psi. Compare that to West System 105/205 with a UTS of 7,846 psi.

    Problem is, CRG, the distributor of Veriflex, no longer sells it.
    Also, what do you mean by Thermoplast?
    Thermoplastic? It is not a thermoplastic.
     
  6. apex1

    apex1 Guest

    Oh, sorry, have forgotten in English it is in fact called thermoplastic. (the rest of the world says thermoplast)

    And of course it is a TP polymer you are referring to. (try wiki on that)

    UTS is not all in boatbuilding you know, and this West formulation not the ultimate competitor.

    Regards
    Richard
     
  7. Paul B

    Paul B Previous Member

    You did? Hmmm....

    Thermoset resins are not thermoplastic by nature. Once set by temperature a thermoset will not transition back to a "plastic" consistency when subjected to heat. It will char and burn.
     
  8. apex1

    apex1 Guest

    They are! Or how do you bring them into shape? By layup like poly or epoxy resin? No by temperature.

    Once "set" of course they are a different creature. But by nature they are thermoplastic polymere.

    And insufficient for boatbuilding btw.

    this may help....
    http://en.wikipedia.org/wiki/Shape_memory_polymer

    Regards
    Richard
     
  9. Paul B

    Paul B Previous Member

    Theremosets are by definition set by temperature. That includes Poly and Epoxy resins. I'm sure you've heard the term exotherm.
     
  10. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    I built carbon/epoxy models for many years. One small model had the hull and deck bonded while they were still in the mold(s). Once, after a cold front had passed I pulled the little boat and the hull was distorted a lot-low pressure on the inside and high pressure on the outside(?). I thought it was junk. Then I drilled a hole in the deck and the thing popped out but the hull was still distorted. Since I had nothing to lose I took a heat gun to the hull skin and it popped out the rest of the way with absolutely no damage whatsoever.
    I was amazed...
    I drilled a hole in the deck mold in way of the hatch so it would never happen again....
     
  11. apex1

    apex1 Guest

    vague.........

    I am only for 35 years in Business now.:D
     
  12. Paul B

    Paul B Previous Member

    Yet you still claim thermosets are thermoplastic ny nature...
     
  13. apex1

    apex1 Guest

    ...that was clear?

    No UV or electric trigger, just heat. Right?

    Then polystyrene and poly butadiene, polyurethanes, polyethylene terephthalate, polynorbornene.... are the common materials in question.

    And these are??:p
     
  14. STRIDE
    Joined: Jun 2010
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    STRIDE Junior Member

    Thermoplastics, I suppose.
    My approach to polymer chemistry has always been from the manufacturing perspective. In manufacturing discourse, a thermoplastic is a material that comes already solid [ie: casting pellets/thermoforming sheets] and a thermoset would be a material that is liquid. Thermoplastics are melted. Thermosets are cured.
    At least that is how I see it.

    Doug: That is very interesting. Partially cured resins have been shown to have shape memory properties, and it is always cool to see a practical application.
     

  15. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ---------------------------------
    I hadn't considered that, thanks. The laminate was done 24 hours before I pulled it so it definitely wasn't fully cured.....
     
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