Electrolysis deck gear carbon G10 Aluminium

Discussion in 'Sailboats' started by NHRC, Aug 10, 2016.

  1. NHRC
    Joined: Jan 2014
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    Location: Lymington

    NHRC Junior Member

    Hi guys

    So I am in discussions with a project manager who insists that it is common practice to bolt Aluminium winches to Carbon boats without an insulation layer of G10.

    Anyone out there boat building at a reputable composite boat yard willing to advise on what they see as good practice?

    Anyone from Green Marine? Ex-Goetz? Baltic? Persico? NEB? McConnaghies etc???
     
  2. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    carbon eats ally...don't do it!!

    Corrosion.jpg

    A potential greater than 50mV is not advised and greater than 250mV is a killer
     
  3. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Yeah, I don't know of any manufacture that's bolting aluminum to anything so noble. The aluminum would literally break down as you stare at it.
     
  4. NHRC
    Joined: Jan 2014
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    Location: Lymington

    NHRC Junior Member

    I believe it was a labour saving cost cutting measure.

    Backfired obviously as they are now rectifying the issue under warranty.
     
  5. CDK
    Joined: Aug 2007
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    CDK retired engineer

    The good news is: graphite boats do not exist!
    "Carbon" boats are made from plastic with embedded carbon fiber reinforcement. The surface doesn't conduct, so there is no electrolysis if bolt holes are sealed.
     
    Will Gilmore likes this.
  6. nota
    Joined: Sep 2012
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    nota Junior Member

    I would NOT on anything like a high loaded hole you hope are sealed
    as it is going to work and ware on the thru deck and soon there is no seal
    and water will get in the smallest gap or crack
    even if the crack is not enough to leak it is enough to cause corrosion
     
  7. tane
    Joined: Apr 2015
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    tane Junior Member

    there will be no "electrolysis", none! Galvanic corrosion maybe...
     

  8. Will Gilmore
    Joined: Aug 2017
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    Location: Littleton, nh

    Will Gilmore Senior Member

    What are the bolts made of?
    The composite material should be well encased in the resin, but drilling through would expose the carbon fibers to the bolts, if they haven't been isolated.
    Electrolysis is the electrical conversion of one material to another by galvanic action. If the anode or the electrolyte or the cathode change, you have electrolysis. However, that's not what sailors care about. It's galvanic corrosion that we care about.
    Notice there are different aluminum alloys with different Nobel values. BS2032 and BS2033 are much better, but pure aluminum is worse than zinc.

    It seems so easy to insulate, so why wouldn't you?
    and lazy.

    -Will (Dragonfly)
     
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