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compound creases in brass bells

Postby bloke » Sun Nov 11, 2018 9:21 am

These can usually be repaired, unless some past "artisan" has already made the unfortunate decision to beat them down flat with a hammer. (MOST OFTEN, it was past "artisans" who were actually to blame for compound creases, as they rolled two creases into one severe compound crease - failing to do the proper preliminary work. yes... Typically, the WORST damage to instruments is done with TOOLS, rather than via accidents or human fingers attempting repairs.)

It's really good to have someone help you hold the bell...

Using one of those old-school "bell irons" (similar to a blacksmith's tool, but flatter and smoother), have a friend hold the bell up at an an angle to the bell iron, with the compound creased area contacting the bell iron.

Using a tool (something like a punch...either manufactured or improvised) with a small blunt/flat end, catch the crest of the compound crease and tap the mound down back in the same direction that it has been raised (typically: at a very steep angle).

Work your way along the crest of the compound crease until all of it has been eliminated. At that point, it won't be pretty. It' then time for annealing and a Ferree's dent machine. If no dent machine put it back on the bell iron and roll it with a long trumpet/trombone bell tapered roll. Roll along the now: partially-repaired area near the tip of the rod using the epic weight of the rest of the rod (the weight being concentrated at the small end, buy supporting the tapered rod in such an unbalanced way) to assist you in smoothing out the remaining mess. It may well require two or three additional annealing processes to make the area look the best it can. It may never be perfect, but it will be far better than a compound crease.
Last edited by bloke on Sun Nov 11, 2018 12:04 pm, edited 1 time in total.
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Re: compound creases in brass bells

Postby YORK-aholic » Sun Nov 11, 2018 10:28 am

It is always interesting to hear (and picture) the process. I can fit and solder things together, but the real work (in my opinion) and skill is in what you've called "De-destroying" horns.

Thanks Bloke.
Some old Yorks, Martins and maybe a rotary King...
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Re: compound creases in brass bells

Postby bloke » Sun Nov 11, 2018 12:09 pm

Quite a few years ago, my first really successful repair of two or three compound creases in a bell was with a Besson 994 bell.
The thick brass made it more difficult, but also (likely) prevented any cracking from occurring.
I still have that bell...Very light sanding (600 to 1500 grit) left no evidence of the damage, and a nice, thick-brass bell.
Much more than "proud of myself", I was very happy to have a saved bell...and such pursuits are not always successful.
Experience never guarantees success.
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Re: compound creases in brass bells

Postby UncleBeer » Sun Nov 11, 2018 12:44 pm

bloke wrote:Quite a few years ago, my first really successful repair of two or three compound creases in a bell was with a Besson 994 bell.


Did you use the dent machine for this? About to invest in proper shop equipment, and wondering how indispensable the Z60 is...
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Re: compound creases in brass bells

Postby bloke » Sun Nov 11, 2018 1:33 pm

UncleBeer wrote:
bloke wrote:Quite a few years ago, my first really successful repair of two or three compound creases in a bell was with a Besson 994 bell.


Did you use the dent machine for this? About to invest in proper shop equipment, and wondering how indispensable the Z60 is...


I'm not so sure that I did, but - with that particular bell - I probably did, but via my typically limited basis.
I use it on bells when I really need some extraordinary muscle to flatten out a particular area...typically, which requires so much "muscle" that - for a bit - I forgo the need for roundness for the need for flatness and - later on - restore roundness with a roller.

I tend to be happier with bells when I..and when possible (as I label - with lack of a better label coming to mind)... "hand-repair" bell flares.

some "hand" techniques involve
- dent hammers (head of the hammer grasped by the fingers) with the hammers' steel tips covered with a rag, and used to push up crests of creases and dents (involving no actual hammering/striking)
- steel roller covered with waxed paper
- repeat, until the wax paper leaves residue on the entire area, with no places - along repaired crease lines - remaining as "shiny places"

Early on (not first - particularly if bell damage is severe), I'll straighten rims with a rawhide mallet. ...I have to use my fingers to straighten most French horn bell rims, though, due (usually) to there being no wire inserted in their rims' beads.

Many men can lift more with their arms than I can, but (I suspect...??) my wrists and fingers are quite strong - were it possible to measure the spectrum of this.
=================================
The BEST thing that those machines do are
- sousaphone branches
- tuba bows
- tuba sousaphone bells (particular the coned portions LEADING UP to the flare)
- Trombone bells (again: particular the coned portions LEADING UP to the flare)

There are many other uses, some of which are quite handy, some of which could be done just as well via other techniques, and some which (to me) seem "gimmicky"...(i.e. "LOOK! It will EVEN do this !!!...etc.)

Often, I'll anneal SMALLER tuba branches/bows and repair them (completely/absolutely to my own not-easily-met satisfaction...) with magnets and very well-greased convex (usually: not spherical) dent balls.

As an example, the last time I un-smashed the lower "J" bow on the back of a 994 (the vast majority of which range from badly-dented to seemingly hopelessly-dented), I used that set of techniques...was completely satisfied, and it was for an instrument that I'm planning on keeping for my own use.
Remaining were two or three severe "cuts" in the surface of that "J" bow, but I filled those with silver braze material....and it's going to be difficult and/or expensive to coax me into going into that much depth of restoration for others. I much more embrace the "do a lot of good for the many" philosophy, than I embrace the "do an epic amount of good for the few" philosophy...and (typically) when I get to work straightening out someone's instrument, 99% of the time they're continuously telling me, "That's good enough right there," rather than asking, "so...You're 'good' with that?" :P :lol:

(If someone wants access my very best work, they might consider watching for an instrument that I restored - some time in the past - for my own use.)
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