Meaning of "Hand-lapped valves/slides"

Discussion in 'Trumpet Discussion' started by [email protected], Dec 7, 2009.

  1. GoodMusic@PA

    [email protected] Piano User

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    Aug 7, 2008
    Hi all,
    I see the term "hand-lapped valves/slides" many times in posts but I never really knew what that meant. Can someone tell me what it means?
    Thanks:-)
     
  2. veery715

    veery715 Utimate User

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    Mar 6, 2007
    Ithaca NY
    It means that the final fitting of those are done by a craftsman and not by machine, if at all. A fine abrasive compound or slurry is applied between surfaces and the parts are worked up and down / in and out to smooth the surfaces where they meet.

    v
     
  3. Brekelefuw

    Brekelefuw Fortissimo User

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    Mar 21, 2006
    Toronto
    It's basically liquid sand paper. Final lapping is usually done with a very high grit, somewhere from 800 grit and up. I think the stuff I use at work is 1200.
     
  4. rowuk

    rowuk Moderator Staff Member

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    With a reputable company, it means that the valves can have a very consistent feel, but not necessarily have the tightest specs.

    If we are talking about the far east, it means that manual labor is cheaper than a maschine.

    If you don't know anything about what is going on behind the scenes at a company, it is just a useless tidbit of information.
     
  5. larry tscharner

    larry tscharner Forte User

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    Apr 30, 2010
    dubuque iowa
    If you ever get the chance to tour or see a vidio clip of a company that does this it is simple yet very interesting. The craftsmen at Getzen were VERY talkative when I toured their shop about a year ago. Do you have a manufacturer within driving distance from where you live? Its well worth the effort to see a trumpet go from brass stock to work of art. Best wishes.
     

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