tiny bubbles

Discussion in 'Trumpet Discussion' started by stricd, Jan 17, 2011.

  1. stricd

    stricd New Friend

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    Oct 19, 2010
    Why am I getting tiny bubbles in the silver plating of my lead pipe? The horn is a 30 year old Getzen cornet that is otherwise flawless, and hasn't been used much. Bubbles are 1-2 mm in size and have been slowly multiplying over the last 4 or 5 years
     
  2. Ed Lee

    Ed Lee Utimate User

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    Varied reasons, but mostly the worst is that the owner(s) wasn't diligent about swabbing the leadpipe immediately after each play.
     
  3. nieuwguyski

    nieuwguyski Forte User

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    expanding on the previous post, the bubbles are an almost certain sign of red rot -- a form of corrosion that will eventually create holes in the leadpipe. When red rot lesions form under silver plate, they make the plating bubble up.

    It can take quite a while for red rot to make a leadpipe unplayable. I've been playing for the last 10 years with a fellow who's playing the lead book in a big band on an old Benge CG with a LOT of bubbled plating in the leadpipe, just past the mouthpiece receiver. The horn had a few bubbles in the plating when I first joined the band, and 10 years later the entire small end of the pipe is looking pretty leprous. This fellow is finally making arrangements with Kanstul to get a replacement leadpipe assembly.
     
  4. SmoothOperator

    SmoothOperator Mezzo Forte User

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    Jul 14, 2010
    Is red rot more of a problem with silver plated horns?
     
  5. Trumpet Dreamer

    Trumpet Dreamer Mezzo Forte User

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    I would not think the finish on the horn would have an impact on any trauma within the interior of the leadpipe.
     
  6. ComeBackKid

    ComeBackKid Fortissimo User

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    True - redrot generally starts on the interior where moisture and other bad influences can collect and remain undisturbed for years and start attacking the zinc content of the brass. Then it works from the inside out. The finish has no effect on the outcome.

    Cleaning it regularly can help slow down the progression.
     
  7. Brekelefuw

    Brekelefuw Fortissimo User

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    Red rot DOESN'T eat through silver.
    What is probably happening is the rot is pretty much through the brass, but the plating is left on top because it doesn't affect it. If it is bad, the plating will be the only thing keeping a hole from being there.
     
  8. stricd

    stricd New Friend

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    Oct 19, 2010
    How do I tell if it is red rot? Is there some way of looking down the leadpipe or testing it?
     
  9. Ed Lee

    Ed Lee Utimate User

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    Many techs now have fiber optic scopes as can be used to inspect the inside of tubing, some linked to video and some just visual. These are a variant of those developed for medical procedures. They call it "red rot" whereas it appears as vermillion red and is corrosive. Swabbing and blowing a little valve oil through all tubing are some deterrents. The leadpipe is perhaps the most sensitive part of an instrument tubing. Brekelefuw is a tech, thus consider his advice wisely.
     
    Last edited: Jan 18, 2011
  10. ComeBackKid

    ComeBackKid Fortissimo User

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    Another way is to remove the tuning slide, position a bright light to reflect off the back side of the bell and into the leadpipe (most bells are large enough to block the line through the leadpipe so you can't sight directly at the light source). If there is redrot, you will see signs of unevenness along the inner surface of the leadpipe. One without it will have a smooth, reflective surface on the inside of the pipe.
     

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