Polyurethane Foam

Discussion in 'Boat Design' started by Bart01, Sep 23, 2008.

  1. terhohalme
    Joined: Jun 2003
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    Location: Kotka, Finland

    terhohalme BEng Boat Technology

    Finnfoam is polystyrene, just better than styrox.
     
  2. KnottyBuoyz
    Joined: Jul 2006
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    Location: Iroquois, Ontario

    KnottyBuoyz Provocateur & Raconteur

    Sorry, my finnish isn't that good! :D
     
  3. Brent Swain
    Joined: Mar 2002
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    Location: British Columbia

    Brent Swain Member

    Most high lattitude steel boats are insulated with polyurethane spray foam. There is nothing better for keeping a steel boat warm and dry in high lattitudes.
    Painting it with cheap latex paints drastically reduces the fire hazzard.
    Brent
     
  4. chada
    Joined: Sep 2008
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    Location: Florida

    chada Junior Member

    BArt01,

    PU foam is widely used in boats. It comes in 2 parts you mix and you pour.
    Example:

    Caorlina skiffs
    Underneath the floor is PU foam. that is what give the skiff to draft so little.

    It is used in many applications from sound supressaint to flotation.

    Hope this helps ya
     
  5. Bart01
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    Bart01 Junior Member

    lololol No prob hahaha
     
  6. Bart01
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    Bart01 Junior Member

    Indeed that's one of the reason why I wish to you PU (instead of Styrofoam ... PU shows better isolation properties. Quite interesting in today's energy issues lolol)
     
  7. Bart01
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    Bart01 Junior Member

    Thanks a lot Chada, would you know where I could find info about all these PU applications? (suppliers perhaps?)

    Thx in advance ;)
     
  8. Fanie
    Joined: Oct 2007
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    Fanie Fanie

    Fiberglass is not waterproof. Over time your boat is going to get heavier and heavier as the foam absorbs the water and you will have to take the foam out again. This foam is also very brittle. If you get a break in it it is going to scharfe away and you are going to be left with a lot of powder. Same reasons why polistirene is not used.

    A much better option would be to fill a cavity with coke bottles, at least they won't perrish if it's flotation you're after.

    See if you can find closed cell pollyethelene foam instead. You can cut to size and glass it in place. Nothing beats it. Weight starts at 25kg/m^3
     
  9. Bart01
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    Bart01 Junior Member

    You mean PU Foam I guess ..? That was one of my fear ... I have already used some for the ground, I planned to do some pannel walls for the isolation ... Could I do anything else with that???

    Bart
     
  10. chada
    Joined: Sep 2008
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    chada Junior Member

    Not really sure why fanie is saying fiberglass is not water proof.
    I believe that of it wasn't water proof then the coast guard would not let companys use to build boats.

    PU foam is used for boats as I said earlier in the blog.
    Here is some info on PU foam.

    2LB density marine foam is recommended for void filling in nonstructural applications. This product can be poured underneath decks and inside cavities where a lightweight flotation foam is needed to provide buoyancy. This foam has been tested in accordance with U.S. Coast Guard Regulation # 33 CFR 183.114 . This foam is approximately 95-98% closed cell which resists absorbing water, however continuous water submersion can eventually lead to loss of buoyancy over a period of years. We recommend this product strictly for flotation applications. If you are looking for a liquid foam for sculpting or casting use 3LB or 4LB density.

    EverCoat
    US Composites

    and there is a couple more companys.

    Hope this helps.

    Chad
     
  11. Wynand N
    Joined: Oct 2004
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    Wynand N Retired Steelboatbuilder

    the gelcoat makes it waterproof or when no gelcoat used, the paint system. You chip or crack your gelcoat and leave it like that, I bet my best hat you will have some serious problems coming your way....
     
  12. chada
    Joined: Sep 2008
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    chada Junior Member

    Wynand,

    Thats IF.

    In general Fiberglass is waterproof.
    If damaged then yes.
    But the overall aspect of it would be fiberglass is waterproof.
     
  13. kengrome
    Joined: Jul 2006
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    Location: Gulf Coast USA

    kengrome Senior Member

    This is ridiculous.

    The foam does absolutely nothing to help the boat draft so little. If anything, the foam will increase the boat's draft as it gradually absorbs moisture and becomes heavier.The only purpose of that foam is to help keep the boat afloat if it gets swamped ... and this is may do if it hasn't already become saturated.

    The Coast Guard has absolutely nothing to say about what materials can and cannot be used in boat hulls, so this statement is totally false and incorrect.

    This claim is also incorrect. Wynand's statement was correct.

    Polyester resin slows the flow of water but it is essentially porous when used in the construction of a composite fiberglass hull. Vinylester slows the flow of water better than polyester but it still exhibits the same type of porosity as polyester although on a lesser scale.

    Epoxy, the best performing (and least used) of all the common resins in fiberglass composite construction, is still not totally waterproof although it is far better than the other two plastics mentioned here.

    ----------------

    Chad, there are many knowledgeable and experienced people in this forum, so when you don't know the facts it is generally better to remain silent and learn ... rather than making claims that many of us know to be false.

    :)
     
  14. rivadezza
    Joined: Sep 2008
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    Location: Thailand

    rivadezza Junior Member

    we use a 2 component foam from finnfoam, its easy to work with and it does not expand like the polyurethan foam.

    send a mail to them www.finnfoam.fi and get a small sample....
     

  15. Bart01
    Joined: Sep 2008
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    Bart01 Junior Member

    Ok I guess most of you are speaking about those sprayable foam, I am more thinking about these rigid panels?

    Thanks for your Help

    Bart
     
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