Expanded Polystyrene Foam

Discussion in 'Fiberglass and Composite Boat Building' started by eyes, Apr 30, 2007.

  1. fallguy
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    fallguy Senior Member

    In the photo, no prep was done. We had some guys here say no prep was needed.

    Typically, we would vacuum a sanded part as it is a heluva mess.

    Even in good marine foams; hardware is best installed in decored areas recored with cabosil and epoxy or cab n milled glass n epoxy.
     
  2. fallguy
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    fallguy Senior Member

    I would never go up in that bird. I'd love to see coupon testing.
     
  3. Jolly Mon
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    Jolly Mon Junior Member

    Keith, that’s an interesting video. And, the narrator says, “it won’t take point loads”. When the XPS is crushed it releases gas from the cells which over time thru expansion and contraction contribute to delamination. It is interesting the loads that it takes. Seems like a delicate flower to touch.

    The fiberglass technique for wetting out and cutting the tabbing was clean. Got to remember that one.
     
  4. KeithO
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    KeithO Senior Member

    The older cloth covered surfaces couldnt take point loads either.....
     
  5. fallguy
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    fallguy Senior Member

    I think that same reason is the cause of the delam in my picture. Some outgassing or some other reason the edge bonds failed related to the xps crushing a bit as the bag pressures are high on the edges. We vac and make a light air blast on all our parts going under vac.
     
  6. fallguy
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    fallguy Senior Member

    I doubt very much the method in the vid would ever be used again since you can achieve better ratios and higher strength with vac.

    The problem, of course, is distortion. The panels can't deform.
     
  7. KeithO
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    KeithO Senior Member


  8. KeithO
    Joined: Jul 2019
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    Location: Michigan

    KeithO Senior Member

    Example of a plane made using this technique doing an aerobatic routine.
     
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