Valve Lapping

Discussion in 'Trumpet Repair and Modification' started by roltrumpet, Nov 16, 2009.

  1. Ed Kennedy

    Ed Kennedy Forte User

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    US Products, Pittsburgh PA - Garnett non-imbedding lapping compound formulated for soft metals, 800 and 1000 grit.

    Then you have to know if, when, and how.
     
  2. tobylou8

    tobylou8 Utimate User

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    A guy told me he used crocus cloth on his valves if they were sticky. I cringed!:-o:?::shock: Was my reaction "justified"?
     
  3. gzent

    gzent Fortissimo User

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    Sounds like a really bad idea.
     
  4. tedh1951

    tedh1951 Utimate User

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    The Wide Brown Land
    Bottom-line it seems, from all these posts - your instrument, do what you like with it but don't whinge when you inevitably stuff up a good trumpet because you have no idea what you are doing.

    I have not read any description here of what I consider to be a complete and correct engineering lapping technique - I did a five year apprenticeship including how to correctly hand lap both hard and soft materials. I have used, and taught, these learned techniques and honed (no pun intended) them over 40 years of engineering practice. Mostly these processes are not taught anymore - manufacturing techniques are more refined, materials are better, we are a disposable society - in the 'old days', stuff was repaired because we HAD to, now it's just thrown away.

    What can I suggest, with respect to my backgound? CLEAN your trumpet regularly, don't eat/drink then play, lubricate moving parts with good quality and appropriate lubricants after cleaning, and above all treat your instruments with gentle respect. If you have ANY doubts (even just a mental niggle) about any if this - get your horn to a quality repairer STAT. :shhh:
     
  5. Kang-Ling

    Kang-Ling Mezzo Piano User

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    Oct 8, 2009
    Frigiliana
    I just made this "Plop-test" (taking out valves with not depressing the valves) with one of my older horns :
    there are "plops", but not very "explossive" ones..

    just blowing air through the trumpet, with (for ex.) first valve pressed and the whole of the 1º slide (with a finger) closed, I can hear some air escaping...(worst is 3º valve)

    the horn has still a very nice sound, but is maybe harder to blow than years ago...

    I do´t know if it´s worth to get the valves newly plated
    ( it´s a Stomvi from 1985, and it costed about 1500$ then, don´t remember.. )

    over the years , I had quiet some repair expenses with this horn, so - now - I am thinking of a limite/stop of repair spendings...)
     
  6. Ralph

    Ralph Pianissimo User

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    Jan 27, 2005
  7. Brekelefuw

    Brekelefuw Fortissimo User

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    Toronto
    This is when the horn is made. When a horn is damaged, sometimes lapping is necessary as a last ditch effort to fix valve issues.
    Probably less than 1% of all repair shops in the world have the capability to hone and plate valves.
     
  8. Ralph

    Ralph Pianissimo User

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    Jan 27, 2005
    I didn't make it very clear, but my main point is that valves are a highly percisioned item and casually hand lapping at home is a mistake. The tolerances are usually very close.

    My second point, which is probably more useful, is addressed with the second video. Keep your valves clean and oiled. If there's a persistent problem, then the horn need professional help.
     
  9. Kang-Ling

    Kang-Ling Mezzo Piano User

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    Frigiliana
    a cheap "solution" for leaky valves is thick oil ????
     
  10. Brekelefuw

    Brekelefuw Fortissimo User

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    Toronto
    If your valves are worn and leaky, a thicker oil will help.
    Hetman's makes many grades of oils, and Yamaha has light, normal and antique grades for example.
     

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