What is Red rot ? what to do about it?

Discussion in 'Trumpet Discussion' started by anthony, Feb 6, 2016.

  1. anthony

    anthony Mezzo Piano User

    Mar 3, 2009
    Hi what exactly is red rot and how do you prevent it from happening
  2. barliman2001

    barliman2001 Fortissimo User

    Jul 5, 2010
    Vienna, Austria, Europe
    Red rot is a deterioration of the brass alloy. In fact, the zinc used in the making of brass is "leaking" out of the alloy, leaving holes. As a first warning, you see red dots appear (the copper remaining after the zinc has gone). When it appears - nothing to be done about it except patching when the hole is evident. How to prevent it? Regularly clean the hooter!
  3. tobylou8

    tobylou8 Utimate User

    Dec 22, 2008
    Some also theorize a players chemistry has something to do with it. You should clean it so you don't find out! ;-)
  4. BrassBandMajor

    BrassBandMajor Fortissimo User

    Jan 13, 2015
    Elmar explained the whole thing. Anyways, brass is an alloy of Zinc and copper. When the Zinc leaves which makes the state called, dezincification. It started make the surface red, if not treated properly in early stage, you will have to replace the area of brass or patch it. In early stages you can remove it with metal polish like MAAS
  5. SteveRicks

    SteveRicks Fortissimo User

    Aug 15, 2009
    Yes, I buy the body chemistry theory. I've owned horns for 40 years and occasionally didn't keep them overly clean. No trace or red rot. I've also bought horns that had red rot, but it never got any worse under my playing, even if they weren't cleaned.

    Comments are not meant to advocate not cleaning your horn. Still, I imagine there are people who are maticulous in maintaining their horn, but still get red rot.

    One think I have wondered. Many say red rot occurs from the inside out. But some horns appear to have it on the outside, but not visible inside. Conundrum.
  6. BrassBandMajor

    BrassBandMajor Fortissimo User

    Jan 13, 2015
    Yes forgot to mention as Steve said sometimes it happens inside. (way more scary)
  7. Ed Lee

    Ed Lee Utimate User

    Aug 16, 2009
    Jackson NC
    Bare brass, wherever it is, will dezincify. In my many years I've replaced many brass plumbing fittings that have corroded. I wear non-porous disposable gloves under my leather work gloves when doing this.
  8. stumac

    stumac Fortissimo User

    Oct 19, 2008
    Flinders Vic Australia
    Dezincification occurs on the outside when the lacquer is chipped or worn through, if it is from the inside it appears as a bright copper spot under the lacquer and as it progresses a black spot will form in the center and eventually form a hole.

    On a silver plated horn the inside rot will form blisters under the silver as it comes through. Some brasses seem to be more prone than others.

    Regular cleaning and drying is the best method of avoiding. The air we breath through the horn contains around 5% Carbon Dioxide which dissolved in the condensate inside the horn forms Carbonic Acid which I think is the main culprit.

    There was a coating available some time ago called "Stop Rot", discontinued before I had a chance to try it.

    The most recent case of red rot I have seen was in a friends Getzen, he had it professionly cleaned 10 years ago and not cleaned it since. My own 70s Getzen Severinsen has a little in the leadpipe just after the receiver, does not seem to effect the playability and not getting worse.

    Regards, Stuart.
  9. Brekelefuw

    Brekelefuw Fortissimo User

    Mar 21, 2006
    Coating the leadpipe and tuning slide with valve oil when you oil the valves will prevent redrot from getting worse.
  10. Dennis78

    Dennis78 Fortissimo User

    Feb 1, 2015
    Doesn't seem like red rot moves fast enough to become very worrisome

Share This Page