Carbon fiber frame clear coat of primer?

Discussion in 'Cycling Equipment' started by Bike2000, May 28, 2017.

  1. Bike2000

    Bike2000 New Member

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    Hi all, I am new here. I have a full carbon-fiber bike. It is after market frame. It's been rode for seven years. There are many scratches ten one spot having the clear layer peeling off. I am thinking about repainting the frame. It's the clear coat is actually a primer? If yes then I don't need to use paint strippers to remove it before painting over it?
     

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  2. dabac

    dabac Well-Known Member

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    No, clear coat is NOT a primer.
    And if its flaking, its no good as a base layer anyhow.
    The edges of the flakes will show up through the new paint - assuming it doesn't keep flaking off.
    I'm not too certain I'd be that keen on using chemical strippers on a composite structure.
     
  3. Bike2000

    Bike2000 New Member

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    Thank for the reply. So my only option is to sand off the clear coat layer with sandpaper?
     
  4. CAMPYBOB

    CAMPYBOB Well-Known Member

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    A LIGHT sanding will not hurt and is the preferred prep for another coat of Clearcoat. Something like 600 grit or very fine scratch pads for final finish.

    A lot of carbon frames receive a light sanding at the factory to clean up mold lines / mismatch and filler resin to fill small voids. What you are wanting to do is blend in and rough up the clear coat and not remove any carbon or resin if possible.

    https://www.google.com/search?q=how...me..69i57j0.7824j0j9&sourceid=chrome&ie=UTF-8
     
  5. Bike2000

    Bike2000 New Member

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    Thanks for the information. I did some more research. It seems sanding the whole frame slightly to even out the surface is the only way to go. Now my question is the spot that the clear coat flakes off is what people call bare carbon? If that's the case should I spray some clearcoat on these bare carbon spots before sanding? I heard it's unwise to sand on bare carbon which will damage the resin of the carbon fiber. Any good clearcoat anyone recommends?
     
  6. CAMPYBOB

    CAMPYBOB Well-Known Member

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    If you use VERY FINE sandpaper and LIGHTLY sand the frame to remove or scuff up the factory clear coat you will not damage it.

    Do not clearcoat prior to sanding.

    It sounds like there are areas of poor adhesion on your frame due to poor surface preparation before it was clear coated. Lightly sand, prep to remove fingerprints/oils and paint. it's really just that simple.

    Go to your local automotive body shop/paint supply biz. Tell them what you are painting...i.e. carbon fiber & resin is similar to a fiberglass auto body. They will sell you the correct clear coat in spray cans.

    You can 'spot in' just the affected areas.
     
    #6 CAMPYBOB, May 30, 2017
    Last edited: May 30, 2017
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  7. Bike2000

    Bike2000 New Member

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    Ah thanks a ton! Is it okay to leave the hard to reach places as is or do have have to sand the frame completely?
     
  8. CAMPYBOB

    CAMPYBOB Well-Known Member

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    As long as your blend and feather the sanded areas into the unsanded areas you will be hard pressed to see the difference after re-clear coating.

    The original issue was one of adhesion. You'll want to be sure to have a clean surface for your clear coat to adhere to.
     
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