Does anyone know a tool to bend brass tubes? I had a look in some
plumber stores in the UK but it seems those tools are suitable for
copper pipes and not for brass.
If the tube benders you saw for copper are for the same diameter
tube as your brass, AND if the brass is properly annealed, they will
work with brass. The bending tools are not highly specific to exact
metals, only to roughly the same degree of hardness. Annealed brass
is close enough. So would be silver and most golds, etc. The trick
will be finding bending tools for the right diameter tubing. THAT
needs to be correct, to avoid crimping and distorting the tube. The
usual types used by jewelers consist of steel strings that fit over
the tube to support and confine it’s shape as you bend it by hand.
There are other methods that work too. Fill the tubes with fine
sand, cap the ends with a bit of wax to hold the sand in, and you
will often find that’s enough support to bend the tube. Same thing by
filling it with water and freezing it.
You will also find that the thicker the wall of the tube, the easier
it is to bend. Very thin wall tubing is harder to do, and often it
won’t take as tight a bend before tearing or deforming too much.
One method I saw on a “how it’s made” TV show that I’ve always
wanted to adapt to jewelry, should I ever need, was shown in how they
make trombones and other brass intruments, where fairly thin brass
tube is bent to the various shapes. It needs to retain it’s very
round shape. They bent the tube in a normal bending tool, which
leaves it slightly deformed, usually slightly oval. Then the bent
part went into a jig, essentially a clamp with the proper tube
profile milled into it. Then, using a press, a ball bearing the exact
size as the desired inside tube size, was pressed into one end with a
press. It was then pressed down further with additional, but slightly
smaller (so they’re loose fits) ball bearings, and this contininued
until the original one pops out the far end, The rest just then pour
out, leaving the tube perfectly rounded. Cool trick. Dunno if I’ll
ever need it, but still a cool idea.