Tales from the Bench #4: Teardrop Trumpet Bell

A couple of months ago, a local music teacher got in touch with me about repairing one of her school trumpets.  A nice Bach student model in silver, the young player had tripped while walking with it, and the bell had received the brunt of the impact. When I met with the teacher, she opened the case, and both of us couldn't help but laugh at what we saw.  As the trumpet is being held while playing, the 10 o'clock position had been pulled up and back, and from the other end the bell was shaped like a tear drop.  Behind the "point" of the tear drop, the bell flare was crumpled like tin foil, almost folding back on itself several places.  The padding of the case was having problems with the bell, as it wasn't built for this shape, and was having a hard time closing.

At that point, I took the trumpet, and went to work.  When the metal has stretched to the point of a crease, it can easily crack and break when trying to pull it apart.  I had to work carefully and slowly to "massage" the creases open.

The first thing needed to pull the creases open was to pull that new point of the tear drop down.  Using a bell mandrel and a very worn in rawhide mallet, I started to push that back into the shape of a bell.  Once that was more or less trumpet shape, I then had to spend the time to open and flatten out every crease, bend, dent and bump.  That was the tedious part, taking 2 hours

Once the dents were about 90% of the way gone, I then started to smooth the metal.  Using roling mandrels and burnishers, I basically ironed the metal back to the smooth surface it was supposed to be.  When I was done, there were minimal scars on the bell.  Once the metal stretches, scars are inevitable, as the stretched metal will always show it has moved.

The teacher got the trumpet back a few days later, and was amazed the bell could be salvaged.  She had been accepting the idea that it could be easier and cheaper to simply buy a new bell and solder it on. 

I love dent work, as it has an immediate feedback of what is happening and what needs to be adjusted for the right result