I'm learning how to fix a beat up trumpet.

Discussion in 'Trumpet Repair and Modification' started by RAK, Sep 2, 2009.

  1. RAK

    RAK Piano User

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    Jul 23, 2009
    Kettle Falls, Washington
    [​IMG]

    In the picture I am planning to unsolder the part where the bell tube connects to the valves. Then I will fill it up with hot lead and make the tube straight. After that I will somehow have to get the lead out and I will take a metal rod the same diameter of the tube and I will Ram the dents out. And after that of course I will fill it up with lead, Bend it back like it was before and Solder it on. Do I use brass wire or steel wire to solder?

    Any suggestions. If I screw up I will earn some serious money and give the horn to the shop.

    Also does anyone have an extra set of dent balls on a wire. I don't think I could afford ferees set.
     
    Last edited: Sep 2, 2009
  2. TotalEclipse

    TotalEclipse Piano User

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    Mar 2, 2005
    Brisbane in OZ
    Don't straighten the bell crook it will wrinkle.
    you will need dent balls to get the dents in the crook out.
    That sort of repair will not need lead to be used.
    You will need a soft solder (lead free) not steel or brass as the melting temp is way too high.
    Look around on the net and you will find more info.
     
  3. Brekelefuw

    Brekelefuw Fortissimo User

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    Toronto
    You are going about this the wrong way.
    Yout don't need lead or any filling agent to fix that damage.
    If you use lead to bend it before you take the damage out, then the tubing will be out of alignment when you do fix it. Restore it to round before you bend it. Working on crooks makes them flair out.
    I know that if you heat pitch after tube bending and you heat it unevenly, for example starting heating the tube in the middle, the pressure inside from the expanding pitch can cause it to explode. We had this happen when I was at repair school with a french horn leadpipe.

    You need dent balls, and a driver/retriever tool, and well as some burnishing tools, a dent hammer or two and a bell mandrel.

    You need solder that is preferably 63/37 lead/tin because that has the same melting and flow temperature. You also need flux.

    On the brace that is connected to the valve block, you really should silver solder that flange back on to the rod for maximum strength.

    This isn't really something that is easy to do with no experience. You don't just get the tubing back in to shape and then resolder it. Putting a trumpet together requires careful alignment to make sure it is put back together stress free and that the slides slide (although you aren't dealing with any tubes with slides.)
     
    Last edited: Sep 2, 2009
  4. ComeBackKid

    ComeBackKid Fortissimo User

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    In addition to all of the above, the small brace which connect the bellpipe to the 2nd valve is going to be tricky. Unless the bellpipe is perfectly aligned, that brace will not be in the correct position. It can be out of position in any, or all, of the 3 coordinates (too high or low, too far forward or back, too far away or too close). If it is not aligned, it will be impossible to solder it solidly or, worse, it can put pressure on the valve casing, distorting it, and cause the 2nd valve to stick. With the amount of distortion that the metal has undergone, it will be a rather tricky operation to put the braces back into alignment. But, as both TotalEclipe and Brekelefuw have pointed out, trying to straighten and then rebend the bell crook would be a disaster. First, such a move would destroy the metal. It would be similar to bending and straightening a nail - it weakens and breaks. Second, even if it were possible, you would need a precision jig to hold the bell pipe so it would bend into the correct position. Third, I can't imagine that if you filled that pipe with molten lead, that you could budge it (they use a hydraulic machine to do such things) or ever remove the lead again - not to mention the cost and also the health hazard of handling that much lead.

    You would better off to find a friendly repair technician and see if he will let you watch, and maybe help, as he does the repair. It will cost far less than what you are planning, it will be successful and the horn will be useable when done, and you will learn the proper way to fix it. I think that you will be very surprised at how it is really done with care, precision, and tools that are designed for such work.
     
    Last edited: Sep 3, 2009
  5. tedh1951

    tedh1951 Utimate User

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    Repair techs sometimes charge more to let you 'help'. :roll:
     
  6. Brekelefuw

    Brekelefuw Fortissimo User

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    What you have said isn't really correct.

    To fix the bell to valve block brace you would unsolder it from the bell and valve block and then silver solder it back together. Then you would fit it back to the horn.

    I didn't point out that restraightening the cell crook would be a disaster, only that it is not a good idea to do with his amount of training.
    A jig isn't required. Just patience and small steps. When the bell stem is bent, it gets put out of round. This means you have to burnish it back to shape, but doing so will make it flare out again. It is a balancing act of going back and forth between bringing the crook into round and then bending the crook to be able to be aligned on the trumpet.


    Lead is soft. Hydraulics aren't needed. If you watch bell making videos , the jigs are usually just a radiussed block of wood. They insert the bell and then bend the bell crook on the wood. There are bending jigs with levers as well, but one can do it by hand. Removing the lead would be a matter of heating it up and pouring it out. There are many other materials that can be used to bend tubing that are safer than lead.
     
  7. TotalEclipse

    TotalEclipse Piano User

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    Mar 2, 2005
    Brisbane in OZ
    Oh yeah...I forgot to mention the lead problems....
    'IF' you need to use lead at some stage you need great ventilation and a respirator at the very least. Lead vapours are nasty.
     
  8. veery715

    veery715 Utimate User

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    In a repair shop (auto) I frequented some time ago a sign:

    LABOR RATE - $30.00/hr
    If you watch -$40.00/hr
    If you help - $75.00/hr
     
  9. gzent

    gzent Fortissimo User

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    Unless the horn is disposable I wouldn't try it.

    I've tried things like this after learning in person from a couple of very capable trumpet builders with mixed results.

    Even if you have the skill to do it, without the right tools chances are that you won't
    get the horn close to being "right".

    If you can live with that then have at it. Using a propane torch, IMO, is the easiest.

    Greg
     
  10. ComeBackKid

    ComeBackKid Fortissimo User

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    Well, maybe it isn't for YOU.;-) But, when I try something like this, my description is how it works out for ME. I was just trying to give the OP a sort of "worst-case" (or maybe "most likely case") scenario. :shhh:
     

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