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utrasonic testing

Discussion in 'Technical Discussion' started by Wireless, Oct 20, 2011.

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  1. Wireless, Oct 20, 2011
    #1
    Wireless

    Wireless Senior Member

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    we have recently finished the forth recent untrasonic testing of the hull on Wireless, an 85' steel aux built in New Zealand in 1985. Each round of testing has revealed areas of concern, especially above stringers with clogged limber holes.
    I can hear the comments now about generalization and particularly, about the limits of point testing however I am going to open myself up for comments and suggestions for minimum thickness of plate, pitfalls and red flags as well as sources of technical information/eduction.
  2. Loren Schweizer, Oct 20, 2011
    #2
    Loren Schweizer

    Loren Schweizer YF Associate Writer

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    Regarding "Minimum Thickness", what you are really looking for is the percentage of wasteage of the original metal.

    No expert here, but 15-20% (or thereabouts) is close to max, depending on which expert/which steel.
  3. Wireless, Oct 20, 2011
    #3
    Wireless

    Wireless Senior Member

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    Thanks Loren,

    By coincidence (good luck rather than good management) I set my meter to "flag" any measurements showing 20% wastage. This seemed fine on the 1/4 plating but a 3/16" plate wasted 20% looks frighteningly thin to someone used to timber and fibreglass.

    I've found plate as thin as 0.100 that would resist a hard slam with the pointy end of the chipping hammer but I'm lying awake at night wondering if I missed any others...
  4. K1W1, Oct 20, 2011
    #4
    K1W1

    K1W1 Senior Member

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    Hi,

    What is Wireless and what has she been called before?

    Is it a Don Brooke design by any chance?
  5. Wireless, Oct 21, 2011
    #5
    Wireless

    Wireless Senior Member

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    You got it K1W1. SV.Wireless ex ACE ex Lollipop. Don Brooke steel motor-aux.

    Currently in Nova Scotia bound for St Thomas.

    And you?