second valve drags

Discussion in 'Trumpet Discussion' started by Jack M, Aug 28, 2009.

  1. nordlandstrompet

    nordlandstrompet Forte User

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    Apr 5, 2008
    Norway
    Lots of good advice given here.

    In addition I will mention that when playing "slow notes"
    the valve action should be just as fast as if you play "Flight of the bumble bee".

    If the valve action is too slow, you will probably push the valve (piston) sideways
    against the cylinder which will make the valve(s) sticky.
     
  2. dwp63

    dwp63 Pianissimo User

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    Jan 7, 2009
    A repair guy told me he uses lapping compound on the inside of the valve casing, I think 220 grit. Maybe somebody can verify this and tell us where to purchase it if that is the case. I did try using some metal polish on one of my slow valves as DH Bailey suggested and that did work on that particular valve.
     
  3. ComeBackKid

    ComeBackKid Fortissimo User

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    May 11, 2009
    Yorba Linda, CA
    That can work in certain very special cases and under very controlled circumstances. Since lapping compound is an abrasive, it is sort of like putting sand in your engine. It will remove metal from the piston and/or the inside of the casing. If the problem truly is interference between the piston and the casing (which is rare on used instruments unless some trauma has occurred), that may help if not overdone. But, that should be a last resort and only used if every other approach has failed and you have confirmed the interference. You can search this forum for information on using a magic marker on the piston to detect interference.
     
  4. ComeBackKid

    ComeBackKid Fortissimo User

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    May 11, 2009
    Yorba Linda, CA
    We all relate. We refer to your infection as the 'N+1 virus'. When I started again after 35 years, I had only one trumpet. That was less than 6 months ago. Somehow, they just keep showing up on the doorstep. I think the word is out that there is a "Brass Instrument Orphanage" being operated at my house.
     
    Last edited: Nov 6, 2009
  5. Ed Kennedy

    Ed Kennedy Forte User

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    Nov 18, 2006
    I'm a repair tech on hiatus. The next time the second valve sticks try pulling up gently on the second valve slide assembly. If the valve suddenly flies up, then it means that the slide assembly got pushed down and is putting pressure on the valve port. Your tech might be able to fix it with the "magic drumstick" cure.

    BTW, a 220 grit lapping compound would be butchery. US Products of Pittsburg has a garnet non-imbedding compound that is terrific. Schilke uses it to lap in new valves fresh off the hone.They use the 800 and 1000 grit compounds. There is also a 600 grit that I used to use on trombone slides with a tight steel mandrel.
     

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