Testing hull thickness

Discussion in 'Materials' started by jenevers, May 31, 2019.

  1. jenevers
    Joined: May 2019
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    Location: Uk

    jenevers Junior Member

    Is it possible for surveyors to test hull thickness these days, without having to use a grinder to create a clean surface? I once saw one grind a good 2 millimeters away before taking a reading! Not my boat I might add!!
     
  2. rxcomposite
    Joined: Jan 2005
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    Location: Philippines

    rxcomposite Senior Member

    Is this steel?
     
  3. jenevers
    Joined: May 2019
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    Location: Uk

    jenevers Junior Member

    Yes.
     
  4. rxcomposite
    Joined: Jan 2005
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    Location: Philippines

    rxcomposite Senior Member

    They use ultrasonic thickness tester approved by the surveying body. Class surveyors do not grind away materials. They ask the shipowner/Master to prepare the surface for testing either by sandblasting or wire brush. 3rd party surveyors do carry a small pick and hammer but only to expose the metal by chipping away rust scales. Only enough for inspection. I have never heard of a surveyor resorting to grinding as the thickness tester will show the state of the plate anyway.
     

  5. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    You need to remove paint and oxidation off for a proper reading. Grinding off 2mm of metal is excessive. On unpainted steel we only scrape off the loose material, particularly when testing underwater.
     
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