Bell annealing


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Posted by Dave on February 03, 2003 at 12:21:58:

Here's a pretty basic question about instrument repair: if a badly creased bell gets repaired and it required quite a bit of metal reworking, does it require annealing to restore the tone of the instrument?

To remove the hypothetical, I have an Alexander 164 with a bell that must have been at the bottom when the horn fell off a shelf. Possibly several times. It was out-of-round, and wouldn't sit on the rim and had some crumpling that had been ironed out. I've worked out the dents (using some polished auto body hand dollies that fit the contour) and reshaped it using some round templates as a guide and it looks pretty good. However, the tone is not the same as it was, and I suspect it is because the bell hardened up while it was being reworked. I'm thinking that when a tuba is made, after all the shaping work, prior to soldering, the factory probably anneals everything. And for a tuba like an Alex,
the resonance of the bell may be strongly influenced by things like uneven hardness.


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