Posted by Rick Denney on February 19, 2003 at 11:07:49:
In Reply to: repair without unsoldering? posted by John Katzenburg on February 19, 2003 at 04:14:24:
The engineer in me has frequently pictured an expandable barrel mounted on the end of a flexible cable, that could be use to push out the dents in the larger outer branches of a tuba.
The problem with it is that it makes the metal yield where it is still soft, which ain't where it is bent. Thus, you stretch the brass before the wrinkle go away. That's why you really do have to hammer the high spots from the outside to move the brass back into shape.
That tells me that the repairman may not know a lot about de-denting brass, and I would be suspicious of him on all other points because of that.
Pulling the bottom bow is a pain, but it isn't that much of a pain. If you are convinced he could satisfactorily remove the dents, then tell him to go ahead and burn the lacquer and just buff off the residue when he's done and give it back to you unlacquered in those spots. You can spot-lacquer it yourself.
But be warned--even after removing the dents, things won't go together without some expert hands. Bows open up when you work them and ferrules won't line up anymore, requiring more work to get them aligned.
Generally, if a repair tech doesn't feel up to a repair, and shies away from doing it with excuses, it may be best to heed his wishes and send it to someone else, even if it requires shipping. The alternative is just to live with the dents, and that really isn't so bad an alternative in the scheme of things.
Rick "who would not want any of his horns to be guinea pigs for any experimenter except himself" Denney