Coremat lay-up

Discussion in 'Fiberglass and Composite Boat Building' started by BEEN.DONE., Aug 29, 2008.

    Joined: Aug 2008
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    BEEN.DONE. Junior Member

    this post is in conjunction with forum "low priced catamarans"

    does anyone know how to lay up coremat?
    there are 1'' to 2'' gaps between the sheets as per pix.
    It appears to me that the gaps in the coremat must be weak points and in fact could it mean the whole hull is weak?

    Attached Files:

  2. tinhorn
    Joined: Jan 2008
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    tinhorn Senior Member

    I'm not an engineer, but it's my understanding that Coremat adds rigidity, not strength. It's a core material - the strength of the part is in the 'glass skins. That layup wouldn't frighten me at all, and I tend to panic easily.
  3. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    You're correct, coremat does a few things, but doesn't really add to the strength of the laminate. It helps make a thin laminate stiffer and will also help hide print from whatever core may be used.
  4. Ilan Voyager
    Joined: May 2004
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    Ilan Voyager Senior Member

    Coremat is a good material for fastly building up thickness in a laminate. A bit brittle but it's not a true problem. The gaps must be absolutely filled with a light putty with some chop mat and/or strips of coremat for the following reasons:

    1/ The inertia (=the thickness) of the skin must be regular with no high variations so you don't have points or lines able to flex along the hull.
    2/ Steps in a core are hard to wet and keep bubbles when laying the inner lamination.

    Don't worry your problem is easy to fix and the strength won't be harmed as is only a problem with a core.

  5. mikereed100
    Joined: Jan 2007
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    mikereed100 Junior Member

    It may be those gaps in the core are where the builder intends to place bulkeads?
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