Carbon Fibre Unidirectional cloth

Discussion in 'Sailboats' started by Ramona, Sep 18, 2007.

  1. Ramona
    Joined: Feb 2007
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    Ramona Senior Member

    Over the years I have had plenty of experience with epoxy resin and cloth sheathing and general lay ups with fibreglass and csm. I picked up a few metres of carbon fibre unidirectional cloth today and intend to do some laminating. It has a thin sheet of what looks like plastic over both sides that seems to be holding the fibres in place. I mixed up some resin and tried out some sample pieces. I just tried wetting though and the plastic seems to be eaten away. In the morning I will test the item to destruction.
    Is this the normal way to use this product?
     
  2. lewisboats
    Joined: Oct 2002
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    lewisboats Obsessed Member

  3. Doug Lord

    Doug Lord Guest

    Carbon uni

    I've used lots of carbon uni on models and full size boats-most purchased thru Aircraft Spruce. I've run into two different versions: 1) the material stitched together at one or two inch intervals,2) the material held together by a scrim of (probably) glass fibers on one side. What they had in common was thin clear plastic sheets on both sides that you MUST remove before laminating. The plastic protects the stuff from getting snagged on itself-which it can do very easily. You probably want to use the uni with some form of woven carbon cloth-makes it much easier to work-particularly if you're hand laying and not using a vacuum bag.
     
  4. Ramona
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    Ramona Senior Member

    Doug,
    The sample pieces I tried last night on strips of cedar worked exceptionally well. No sign of the plastic. I tried laying a piece onto wet resin and then soaking through from the top. Another piece was just the carbon laying on a dry piece of cedar and I wet it through. In both cases the carbon wet out well. When I tried to tear it off this morning it only came away with great effort and brought all the fibre with it and a layer of cedar.
    I tried to pull this layer of plastic off before I started and it didn't want to. Its only thin like cling wrap.
     
  5. Ramona
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    Ramona Senior Member

    Just for those people interested in working with carbon fibre. Yesterday I put one full lay up over my Finn carbon mast. Tricky stuff to work with. Does not wet out like cloths so its hard to see exactly how much resin goes on. I just slopped it on and squeegeed the excess off. Generally very impressed with the results. The thing is not to be scared off from trying this yourself.
     
  6. Spirketting
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    Spirketting New Member

    Carbon Fiber cloth over Fiberglass

    Interesting post.

    I have some repairs to do this winter on the outside of my 14' fiberglass hull.
    The hull is old and thin and some stress cracks are letting water seep in. I was planning on repairing the areas with conventional fiberglass cloth and West Resin. I am wondering now if there would be any advantage to using carbon fiber cloth -or maybe even a carbon/kevlar blend-rather than fiberglass. I am not very concerned with appearance, I just want maximum strength and durability. I also am looking for any excuse to try out some of these materials!

    Has anyone experimented with carbon over fiberglass? If so, how did it work?

    cheers,

    matt
     
  7. KnottyBuoyz
    Joined: Jul 2006
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    KnottyBuoyz Provocateur & Raconteur

    Pretty sure it'll work like any other fabric in a repair. Epoxy is the key. The carbon/kevlar fabrics will float in the resin though. You'll need to vacuum bag or infuse it to ensure a proper resin/fabric ratio for strength. Much easier to do if you can flip the boat and let gravity help. Real bugger working overhead with a thoroughly wetted out fabric falling on your head! :p

    Good luck, post some pics if you can.

    Rick
     
  8. DGreenwood
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    DGreenwood Senior Member

    In this case carbon would be of no value greater than ordinary E-glass In fact, depending on the size of the repair, the flexibility of the hull, and how well you feather in your repair, it could be a negative to have a very stiff patch in your hull.
    Stick with vanilla!
     

  9. Spirketting
    Joined: Sep 2007
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    Spirketting New Member

    DGreenwood, Knottybuoyz,

    Good advice. I plan (temperature permitting) to do the job outside on the dock, so happily for me the boat will be upside down and make it a bit easier to get it sufficiently, but not overly, wetted.

    As cool as the carbon stuff is, I think I will use it in another project process and stick with ~9 oz Fiberglass cloth for this job.

    (off to reread my gougeon bros. "boat construction" book. . .)

    cheers (I will post pics),

    matt
     
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