Work Hardened bell flare repair

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posaunebone
Posts: 90
Joined: Fri Jan 25, 2019 1:38 pm
Location: Chicago, IL

Work Hardened bell flare repair

Post by posaunebone »

I have a early 36 that someone had been putting the slide in the case backwards for years, so the tenon banging around against the bell made a pretty sizeable area that's been work hardened. Some visible marks on the inside of the flare too on some heavier impacts. Easiest way to describe it is a rough flat spot. I didn't have my tech go too far on it since I have plans to eventually refinish the bell and figured annealing or something else might have to happen so leave it until then.

I would presume that this would be a situation where the bell flare might need to be annealed to allow for a roller / burnisher to actually smooth things out. Has anyone had something similar worked out and noticed any playing differences when that large of a section has to be annealed? Bell plays great so I'm also wondering if this is not really worth attacking and just going to be an ugly bell to deal with.

Thanks in advance!

Here's a couple pics from when I submit my shipping damage claim that might help clarify what I'm talking about.

https://drive.google.com/drive/folders/ ... Ze2P7ZOGop
Posaunus
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Location: California

Re: Work Hardened bell flare repair

Post by Posaunus »

Mike,

Bell plays great? You may just as well choose to live with it as is. :idk:
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BGuttman
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Re: Work Hardened bell flare repair

Post by BGuttman »

For that kind of damage you shouldn't need to anneal the bell. Check out the Wes Lee videos. He doesn't use heat on damage that is much worse.

Note that the dent removal will result in more work hardening.

Refinishing the bell will involve a lot of polishing and a new layer of lacquer which may be of a different thickness than the one you have now -- and may change the playing characteristics.

There is no free lunch. Anything you do can change how the horn plays. You have to decide whether your eyes or ears matter more.
Bruce Guttman
Merrimack Valley Philharmonic Orchestra
"Almost Professional"
hornbuilder
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Joined: Wed May 02, 2018 9:20 pm

Re: Work Hardened bell flare repair

Post by hornbuilder »

The only way to repair such damage is to anneal the area.

Understanding that we're talking about an area maybe a few square inches in size, (the whole flare is not annealed) such work is not going to change how the horn plays.

Yes, it would burn the lacquer (if it is present) so that would need to be addressed.

I have done such repairs on numerous horns. I've yet to have a client say the horn was negatively affected.
Matthew Walker
Owner/Craftsman, M&W Custom Trombones, LLC, Jackson, Wisconsin.
Former Bass Trombonist, Opera Australia, 1991-2006
Crazy4Tbone86
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Joined: Tue Jan 14, 2020 10:52 am

Re: Work Hardened bell flare repair

Post by Crazy4Tbone86 »

Exactly what Matthew said!

I'm sure many of you remember the old Bundy trombones that were engraved "Designed by Vincent Bach." Those poor horns took a beating on the bell flare because the slide would bump into the bell while inside the case. Many times, the young player would leave the mouthpiece in the receiver while it was in the case and the bell took even more of a beating. The result was a flat spot on the bell that was extremely work-hardened.

I saw hundreds of those when I worked at Music & Arts. I would anneal that section of the bell, work the dents out, relacquer the spot on both the inside and outside of the bell, and then send the instrument out to be rented by another student. It worked very well and the horns played nicely after the process. That is.....until the next student would store the mouthpiece in the receiver and the process would start all over again.

Back to the original post....I am surprised that posaunebone says "the bell plays great." My experience has been that bells with work-hardened flat spots tend to play tight and can be rather touchy during hard articulations. If the flat spot has not impacted the way the bell plays, posaunebone should consider themself very fortunate!
Brian D. Hinkley - Player, Teacher, Technician and Trombone Enthusiast
posaunebone
Posts: 90
Joined: Fri Jan 25, 2019 1:38 pm
Location: Chicago, IL

Re: Work Hardened bell flare repair

Post by posaunebone »

Yeah I was pleasantly surprised given the shipping damage and that work hardened spot! It is a very early Elkhart (in the 9000's) so I'm sure there's some magic to the brass itself. Plays similarly to my early 42 bell (which shouldn't be too surprising since that's a 60's early elkhart bell in the 6000's as well) but with the color change I was looking for for when a medium horn might be needed.

Thank you all for validating that it is not a goner. For now, it'll be a bit of an ugly patch on the bell, but given it's modular conversion / relacquer future, I'm sure there will be a chance to clean things up.
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