Posted by Art H on June 04, 2003 at 23:20:04:
A young student of mine has a Weril BBb about a year old, with a double-padded gig bag. She accidentally set it down too hard one day, causing the bell and tuning slide to be pushed in a couple of millimeters. The only visible sign of damage was a slight bulge inside the bell, where it is connected to the top bow. That slight displacement put some stress on the first piston (since the leadpipe is connected to the bell) causing it to stick. It was moveable, but not free.
So here is my question for experienced repairmen: Is it best to lap the valve, or would it make more sense to unsolder the leadpipe and tuning slide, taking the stress off the valve, so that it might just spring back into its proper shape?
I would have tried the latter approach if it were my tuba, but the repairman she took it to spent three weeks lapping the piston. What do you think?