Why evidence of dent removal?

Discussion in 'Trumpet Repair and Modification' started by radiobob, Jan 17, 2005.

  1. radiobob

    radiobob New Friend

    Why do so many old horns have evidence of dent removal? Is it possible to completely remove all trace of dents? Or are some just being lazy?

  2. KAdams4458

    KAdams4458 New Friend

    Jan 13, 2005
    With enough effort, nearly all evidence of dents can be removed. To my knowledge, there is only one real reason why so many horns have shoddy dent work. The majority of repair techs simply lack the ability to do better work.

    I have seen a trumpet that was thrown to the other side of a paved parking lot during a high school brawl come out of the repair shop with not so much as a slight distortion to be found anywhere. But, I have also personally had a horn ruined by well-meaning repair techs who "overhauled" my very first trumpet. It came came back to me with ripples everywhere and had been seriously over-buffed.

    Removing dents from a horn is not just a technical matter that anyone can master. I feel that it's a form of art.
  3. Robert Rowe

    Robert Rowe Mezzo Piano User

    Dec 24, 2004
    I asked my wife, who is a graduate of Red Wing Technical College (MN) Band Instrument Repair ...
    She informs that small &/or minor dents can usually be removed with no resulting "tell-tales". Severe creases and such -- usually to the bell flair -- can be removed and the affected area can actually "feel" (a term that she uses often, as the techs are trained to use their sense of touch a great deal) as though there had been a total removal of damage, but, invariably, a "scar" will remain. This is because the metal has experienced a "molecular re-arrangement" or "trauma", and the brass-alloy has a "memory"... hence, the "wavy lines" and such evidence as we see. The metal has been "stretched" and is trying to return to it's earlier configuration. She related stories about doing repairs on damaged horns for their tests and exams -- everything corrected and "play-tested" to satisfaction, only to find the horn "out-of-whack" the next day, or a few days later. The student-techs quickly learned to turn in their repair work immediately to the instructor for examination, rather than wait another day-or-so.
    I have accompanied her to various NAPBIRT clinics and tech-seminars (at cost to me as a "guest"), to learn more about brass-repair. The "hot" thing now is Magnetic Dent Removal Balls, which is really cool. I even tried my hand at it at one of the sessions, and was surprised to have done a pretty fair job; although, it is obvious it would take a lot of practice to be really good. The thing about this M-D-R system, though, is it is dangerous... I saw some experienced techs get their fingers smashed. The magnets are super-powerful. No body-pierced metal is permissable (nor jewelry), as you might imagine. (Tatoos are not a problem, other than the visual pollution).
    I now do some of my own repair work, but one must invest in many specialty tools -- and they are all expensive.
    Repair techs are hard-working people. Look for one that is "NAPBIRT"-certified. It's like a "board-certified" surgeon in the medical profession.
    The NAPBIRT certification will be proudly displayed at the shop.

    Hope this helps.

    Robert Rowe

    P.S. - "Hello, Bob"! I'm still digging my Super 400's!
  4. Tootsall

    Tootsall Fortissimo User

    Oct 25, 2003
    Yee HAW!
    Too bad this topic didn't get any more "play" in TM. Over in TH it is now several pages long and includes some really good stuff by Leigh. I don't "like" referencing back and forth between the two sites but there is some good info... perhaps Leigh would like to copy his response over here? (When he has time from building and restoring horns, of course!) ;-)

    I'll add my comments with respect to Robert's about the magnetic dent removal... I've not seen it in person but have seen video clips of it being done... pretty amazing stuff. As long as the user is careful (ie... PAY ATTENTION TO WHAT THE MANUFACTURER HAS TO SAY ABOUT SUPER-MAGNETS AND WHAT ROBERT SAID ABOVE!!), it should be a very useful tool for the local "quick in and out" repair shop. Still, I don't think it can replace a craftsman such as Leigh who will remove the "offended against" part from the instrument and actually hand-burnish the bell or tube before buffing and refinishing!

    (Supermagnets... rare earth type... we use them at work to remove anything faintly magnetic from our finished product.... many times more powerful than "plain ol' fishing magnets".... and have the same warnings about caution when around them!)
  5. eclipse trumpets

    eclipse trumpets Piano User

    Oct 24, 2003
    Hi all

    This is a tough question to answer as no 2 dents are the same!
    Each horn will have different thicknesses,different materials used, maybe it has been worked on before?

    I think that given the right time on any horn that you can get just about anything looking as new.
    I have stated on TH that not all techs are of the same standard, i think a poster here has pointed that out also.
    In the UK we have hundreds of people who say they are repairers but i would not send my work to 95% of them to be honest.
    Training schools here are not good in my opinion, the teachers in many cases cannot repair themselves and send their own repairs to the likes of us or a couple of other places.

    I am not for one second saying that i know it all! i am still learning every day, but i have had hands on experience working with brass day in day out since i was 15 years old.
    Instrument repair takes a long time to learn and even if you have a natural ability with your hands to start with you will need at least 7 years to grasp the basics (my opinion)

    Repair tools have advanced in some areas over the last 5 years particularly (magnetic dents balls etc etc) but i would say to the guy whose wife has been to repair school, that learning how to achieve the same results the old fashioned way first will be a great advantage to her in the long run as some of these new tools will never be able to take the place of a skilled hand in certain areas.
    Using those new tools are essential of course, but i think she would be wise to explore all techniques and become a highly skilled tech (of course she may well be doing just that?)

    Back to the repairs!

    Its the same in any trade, there are fantastic people, average people and other who should maybe find a different career.

    95% of our repair tools at Eclipse are hand made by ourselves, this enables us to not only save money but to make them perfect for the jobs we design them for.
    We do have new tools, but if they were melted down in a furnace tonight while we slept, we could still open up the workshop in the morning and carry on doing exactly the same quality in exactly the same time because we know how to do all the repairs with our hands and handmade tools.

    As always, just my own thoughts!!


  6. radiobob

    radiobob New Friend

    Thanks, guys for the replies, very interesting. I don't get over here to TM much yet, but I'm trying to cover both forums more, it is amazing the difference in replies between the two forums. Robert and Leigh, I'd like to know more about your experiences learning to fix horns. I'm finding it very hard to find the resources to learn. It's humbling to hear you say it takes so long to learn. I just want to work on trumpets and cornets, and do mostly basic stuff, be able to tweak and fix my own horns. I already do some things, but dent removal and soldering I still can't do, of course. I'd like to know more about building your own tools, I'd assumed that most of the ones I've seen could be made at home.

  7. Robert Rowe

    Robert Rowe Mezzo Piano User

    Dec 24, 2004

    This is tough. Here's my experience regarding horn repair...
    I, too, wanted to work on / repair trumpets, cornets. I have worked in the construction (civil engineering, commercial/residential construction)
    business for quite a while. I was looking for something more rewarding / less "crazy" / challenging ... maybe, not as much money, but that's OK.
    I'm an "East Coast guy", and in construction (especially being single), one can move around from place-to-place, usually where the money is good and the locale is comfortable. I worked in Virginia, Maryland, Delaware and New York. Years ago, I was heavily "into" vintage guitars (still am, somewhat less so), and I would get off the Interstates and Turnpikes in my traveling, and stop in small-town music stores, looking for interesting guitars & amplifiers (and found plenty). I struck up friendships with many of the owners, and they would call me if they happened to take in trade something I was looking for. I began to notice these stores were primarily guitar-oriented, with some, but not many, horns -- saxes, trumpets, cornets, etc. Almost always, they seemed to be reasonably priced, as the store-owners just wanted to get some money in return for their trade-allowance on a guitar sale. The horns usually needed some repairs, and I learned the owners had difficulty finding local brass & woodwind repair techs. A few tried themselves, and usually did poorly.
    I decided to look into what was necessary to become a repair-tech -- I was already reasonably proficient at guitar repair. I thought the Old World guild system would be in effect (where one begins as an apprentice, and gradually learns enough to be qualified as a regular repair technician. ...Wrong ! Almost non-exisistant. So, the next idea was to find a school that could teach me. I was already quite skilled at working with wood, and could solder, braze, and weld metals. I was living and working on the East End of Long Island ("The Hamptons"), and could catch some fine surf out at Montauk Point (in spite of the Great White sharks there). I learned there was a school, Five Towns College that had a band instrument repair course of study, and I figured I could still work part-time at construction and free-lance bartending (nice money & great opportunities for picking-up "babes"). Unfortunately, the head of the department just had a stroke, and the college closed that course of study. Alas. Research turned-up nothing East of the Mississippi. As a matter of fact, there are very, very few schools in the entire world that teach band instrument repair. Some are: Red Wing Technical College in Minnesota, Western Iowa State College, Renton Techncal College in Washington state, and another I don't recall in British Columbia, Canada.
    To learn more, pls visit the website for the Nat'l Assoc of Professional Band Instrument Repair Technicians at www.NAPBIRT.org.
    This is a long, long story about how I arrived at the present level of repair knowledge. But, I will complete the saga tomorrow. I have to get up early to deliver a guitar about 100-miles away in central New Jersey, and it is forecast for major snow later in the day, Saturday.
    ...to be cont'd....

    Robert Rowe
  8. trumpetmike

    trumpetmike Forte User

    Oct 11, 2004
    Farnham (a place too smal
    Spoken like a true musician - are you sure you don't play?

    Having seen repairs from many UK repairers, Leigh is one of only three that I would trust with my instruments - and I have tried out far too many.
  9. mike ansberry

    mike ansberry Forte User

    Dec 30, 2003
    Clarksville, Tennessee, U
    I didn't attend a repair school. I learned repair in the late 1970's from an old guy, Peg Meyer who was trained by Conn in the 1920's. I worked for him for several years before I started out on my own.

    Peg used to use the term "work hardened". He said that the spots of the metal where the work was doe got harder than the rest of the piece. He said that you could fix this by re-annealing (-5 points for bad spelling) the piece to return the molecular structure to the way it was. Seems like a lot of trouble when you can replace the piece.

    On a silver horn, I can usually get the dent out to the point that it is very difficult to tell where it was. It helps that you can buff up the silver on a plated horn. On a lacquer horn, the lacquer will crinkle up and get "cracked glass" look to it. If you remove the old lacquer and relacquer it you can't tell where the dent was. You still have the underlying problem of "work hardening" and the sound of the instrument can be affected.
  10. Daff

    Daff Pianissimo User

    Jul 10, 2004
    Exactly, but a metal can be stressed (stretched) beyond the point where it will return to its original shape. This point is referred to as the 'moment of elasticity'. If stressed beyond that point, the metal will be permanently disfigured.

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