Dent balls?

Discussion in 'Trumpet Repair and Modification' started by RAK, Aug 11, 2009.

  1. RAK

    RAK Piano User

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    Jul 23, 2009
    Kettle Falls, Washington
    In music stores when there's dents they take a magnet and several small metal balls and drop them in and fix dents with a magnet. Does anyone know where I can get these. If you got some maybe I could buy them? Anyone know any online stores. I got a huge magnet. just need the spheres. They all come in different sizes I beliieve. :oops::oops::oops:
     
    Last edited: Aug 11, 2009
  2. Brekelefuw

    Brekelefuw Fortissimo User

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    Mar 21, 2006
    Toronto
    I wouldn't waste your money.
    THe MDRS (magnetic dent removal system) is expensive ($300-$1000) and only works on specific kinds of dents. I have never seen it used on a trumpet because the magnetic force isn't strong enough on the size of balls that fit into a trumpet.
    When I use MDRS it is on tubas. They are also good for saxophone bows.
    The whole MDRS system comes with a few different sizes and shapes of magnets as well as some balls. I highly doubt your magnet is as strong as those provided in the kit. These magnets will zap a phone or credit card from 2 meters away. They will also crush your fingers should they get in the way of a dent ball.

    Most trumpet work is done with rods, cables, balls and hammers.


    And please, next time give your topic a title that at least tells us what it is about...
     
  3. cobragamer

    cobragamer Pianissimo User

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    Jan 26, 2008
    Raleigh,NC
    It could be could confused as spam or something worse.
     
  4. ComeBackKid

    ComeBackKid Fortissimo User

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    May 11, 2009
    Yorba Linda, CA
    I believe the MDRS uses a pulsing electro-magnet to sort of hammer the dent from the inside. A permanent magnet doesn't provide the impulse required.

    P.S. I second (or third) the motion about the title - it's sort of tacky.
     
  5. Brekelefuw

    Brekelefuw Fortissimo User

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    Toronto
    MDRS is a huge rare earth magnet (weighing probably 3-5 pounds) encased in a pvc shell that has a steel handle on it. You can attach a longer steel hammer to help increase the strength of the magnet. Feeding more balls down the tubing also increases the strength.

    To get the dents out you rub the magnet back and forth over the area like a child could colour with a large crayon. The dent gets rolled up between the magnet and the balls.
    There is no electricity involved nor is there pulsing.
    It only works on soft dents such as one that would be caused by something like banging the horn in to a pole. Any sort of creasing is too sharp for the balls to work on, and they have to be taken out by normal means.

    If you don't coat the horn in a lubricant or some sort of covering, the lacquer will get rubbed off.


    Here guys, go nuts. This is a top of the line MDRS set

    http://www.musicmedic.com/catalog/products/tool-d153.html
     
  6. vntgbrslvr

    vntgbrslvr Piano User

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    Oct 10, 2008
    Waukesha, Wisconsin
    I don't believe the dent balls used would be large enough for reasonable force to remove dents in a trumpet. The only examples I have seen manipulated were large brass where the steel balls have more mass than the magnets. One other caveat. It's just as easy to do severe damage with a powerful magnet as it is to fix...including yourself.

    More information on the up's and down's of Magnetic tools.
     
  7. Brekelefuw

    Brekelefuw Fortissimo User

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    Mar 21, 2006
    Toronto
    MDRS FAQ

    If you read the second question, it explains why MDRS can't be used on trumpets or trombones.
     
  8. RAK

    RAK Piano User

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    Jul 23, 2009
    Kettle Falls, Washington
    So you guys are saying it is impossible to remove dents in Small tubes of a trumpet and other small instruments? Would the only way be cutting it and fixing the dents?
     
  9. vntgbrslvr

    vntgbrslvr Piano User

    267
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    Oct 10, 2008
    Waukesha, Wisconsin
    No one said it was impossible....just that it's currently impossible with a magnetic dent removal system.

    There are all kinds of tools for brass instrument dent removal.

    There used to be some better videos but this one shows some rough bell straightening.

    Smaller tubes typically use dent balls dent rods, and small dent hammers to fix the dents.
     
  10. mike ansberry

    mike ansberry Forte User

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    Dec 30, 2003
    Clarksville, Tennessee, U
    No, you wouldn't cut it. A repairman uses steel balls that are graduated in size. They are usually attached to a handle by a long, narrow, spring type device that screws in to the handel. You run a metal cable through the hole in the ball. You push this into the tube. Start with a ball that is small enough to barely go past the dent. Then switch to the next bigger size, and again, and again...You can push the dents up this way. It is sometimes necessary to use a dent hammer and a burnishing tool to finish the job. IT REQUIRES HAVING "A FEEL" FOR THE JOB, OR YOU CAN MAKE A MESS OF THE INSTRUMENT.
     

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