Advice for BELL repair tools

Discussion in 'Trumpet Repair and Modification' started by Osren, Dec 2, 2012.

  1. Osren

    Osren Mezzo Forte User

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    As some of you remember, awhile back, I posted asking about dent balls and removing dents and I received some excellent advice. I bought some of the recommend tools and I'm getting pretty good at removing dents in the the "crook" area and other areas that are the correct size for my dent balls to knock out.

    NOW, I'm interested in learning more about Bell Dents and Dents in the first 6 inches of the tubing after the bell (too big for my dent balls to work on)


    I know I will need some hammers, mandrels, burnishers, rollers, irons.... or some combination of them. Ferrees and Votaw Tools seems to be the easiest places for me to get these specialized tools. If you know of another place that us NON repair shop types can order from here in the states, let me know :)


    I've been looking in Ferreestoools catalog and once again scouring the net and various brass forums to see what others have said and suggested.
    Page 31 has many of the bell working Mandrels...

    My initial thought was I need Ferrees P71 Bell Flare Mandrel for Cornets and Trumpets
    [​IMG]

    but I have found some posts (on a trombone forum) that seemed to suggest that the Universal Bell Iron is used more (now that MAY just be a trombone thing... or maybe it's true of trumpets as well)
    Ferrees L5 Universal Bell Iron

    [​IMG]

    Page 32 has some universal Tapered mandrels....
    Page 33 has the N91 tapered Mandrels
    [​IMG]

    So with that as a starting point... I'm asking all you guys that actually DO this sort of work, what do YOU use? I'm not looking to fix a totally crumpled bell, I want to straighten a bent bell rim and fix small to medium dents along the bell and the tubing following it to say where the pinky ring is on the lead pipe. If you can make some specific tool recommendations that I can start with (mandrels,hammers,burnishers,etc... ), that would be very cool.

    Remember, I don't plan on opening a shop, I really just want to learn how to do this.... I don't plant on working on anything of value at this point. I have some Olds Ambassador Trumpets/Cornets and a few other fixer uppers that are here just calling for me to do some work on them. ;)

    I'm watching what I can on Youtube on HOW to do this type of work.... once I get the tools, I will probably start asking more about this.... ;)

    As always thank all of you for your kind words and helpful input!
     

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    Last edited: Dec 2, 2012
  2. stumac

    stumac Fortissimo User

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    Hi Soren,

    I made my own tapered mandrels from scrap mild steel bar of whatever sizes I could find/scrounge, 3 different sizes that do all bell work for me. I will measure them and post later, you can compare them with the commercially available ones. Postage from USA to Aus would be more than the cost of them.

    Build up your tools as you need them, the only ones I have bought are a set of dent balls and driver, a small hammer from Votaw, a curved Burnisher and small hand held gas torch from a local jewellers supplier.

    Regards, Stuart.
     
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  3. stumac

    stumac Fortissimo User

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    Hi Soren,

    here are the measurements of my mandrels, there was no science in determining the tapers, just an approximation to bell throat taper at various places along its length. The Ferrees L5 bell iron looks good, I have an old flat iron I may just convert.

    1/ 1-1/4" dia stock, 16" long tapering from 1-1/4 " to 0.85" over 8-1/2".

    2/ 1-1/8" dia stock 20-1/2" long tapering from 1-1/8" to 1/2" over 13".

    3/ 7/8" dia stock 22-1/2" long tapering from 7/8" to 0.475" over 11".

    Plus an assortment of 5/8", 1/2", 3/8", 5/16" and 1/4" dia rods of various lengths, some threaded for my homemade dent balls ( an assortment of reclaimed bearing balls), some drilled and tapped for attachment of my commercial balls.

    Regards, Stuart,
     
  4. Fohqudill-Instruments

    Fohqudill-Instruments New Friend

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    All of the tooling mentioned is what we use and you cant go wrong but practice first and if so try and get some tuition on using the tools correctley, I would say to go a get a magnetic pen, this way you can feel that you have 100% metal to metal surface contact between the bell and mandrel...that way your not going to burnish the material inwards....another little trick is to put a laser on your vice aiming at the area on the mandrel that is closest to where you want to smooth out on the taper.
     
  5. trumpetsplus

    trumpetsplus Fortissimo User

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    If you are looking at the first 6 inches, my first suggestion is a rolling burnisher. I only ever use the bell mandrel for straightening out the bell wire. Then for the next couple of inches past where the rolling burnisher won't fit, push the dents up with a smooth round rod (the bigger the better). You will see the bell tubing move where the rod is pushing.
     
  6. Osren

    Osren Mezzo Forte User

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    thanx everyone that has replied.

    stumac, I really appreciate you going out and measuring your mandrels, that gives me a GREAT starting place for those.

    Fohqudill-Instruments, I had never considered the laser on the vice, I have been using some magnets already with my dent ball set (just to see where the darn dent ball is in the tubing) and it works great!

    Ivan, as always, your advice is great. I think I may forgo the bell stem mandrel for the moment and work on getting a rolling burnisher....

    Ivan which TYPE of rolling burnisher are you referring to... Ferrees Page 23
    the P2-P10 Double Handle and Cone Shaped Rollers (if so, which one would I start with)?
    OR
    the P11-P12 Dent Rollers? (I would assume if it is THIS type of roller, it would be the P11 as it is shorter then the P12.. but I could be wrong...)

    Once again, thanx everyone for your advice, and PLEASE keep it coming! :)
     
  7. Brekelefuw

    Brekelefuw Fortissimo User

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    I use the P11, and the P3 and P4 over a bell taper mandrel for work past the flare.
    A great use of the P11 on the bell flare right up to the bell rim is in conjunction with a bell iron.
    Make a sleeve that fits over the P11's handle so it is longer. Mount the bell iron in the vise with some static tape over it to protect the finish if your iron isn't polished.
    Hold the P11 on your left hand with the stem of the P11 resting on your shoulder and hold the trumpet by the bell throat with the front of the bell facing upwards. You stand at the high edge of the bell iron with the trumpet on the other side of the iron. It should be mounted at 60 to 90 degrees from horizontal.
    Twist your hand holding the trumpet back and forth as you slightly rock back and forth with your whole body. This lets the bell rotate between the iron and the P11.
    This is a great way to do final smoothing work on a bell flare, and is a poor man's Z60 dent machine to a certain degree.
    I use heavy key oil on the bell iron as well to facilitate the rotating action.
    You can work from the bell rim to as far as the P11 will fit in to the bell throat with great results.
     
    Last edited: Dec 3, 2012
  8. trumpetsplus

    trumpetsplus Fortissimo User

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    Hah - If I use my dent machine does that make me a rich man? I used to do similar to what Brekelefuw describes above.

    I use a 7" roller as my "go to" tool for minor bell work. Sometimes for major concertinas I stretch the bell out by hand before going to my undent machine.
     
  9. Brekelefuw

    Brekelefuw Fortissimo User

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    A dent machine does make you a 'rich' man because it shortens the time needed to remove dents by a pretty big rate.

    I use our dent machines as well (we have 2 of the Ferree's ones and an old Eric Brand one,) but I doubt a hobbyist would invest the thousands needed to get a full dent machine setup.
     

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