On 4/18/08, neil N <musomuso@gmail.com> wrote:
>
>
> As for bending, the conical tube for the tuning slide was filled with
> lead, bent on a jig (by hand). (of course it was annealed first.....
> and the seam was bronze brazed) As it was bent, it was removed so the
> high spots could be tapped down. Then bend. Repeat. THEN we used a
> hardwood chunk (a section from a tree trunk. Really!!) as a base and
> using hooks and a hammer, we "rounded" the piece out some more, then
> we would go to the filing, emery, buffing stage. I might not be
> recalling all the steps involved, but just for that part, it was
> somewhat labour/time intense.

There  is a video running on Discovery Channel on making trombones. The
featured
company filled the pipes with water; froze them; and then bent to shape.

BenT