My favorite solder for brass comes from a welding supply store –
1/16" Lincoln Low Fuming Bronze brazing rods (BARE RBCuZn-C).
Despite their being called “bronze,” they are a brass, as indicated
by the zinc content, and are a decent color match for brass.
However, they can only be used with red brasses, with a high (85% or
more) copper content, because standard brasses (which contain more
zinc and sometimes lead) have lower melting points than the brazing
rods do. The brazing rods can also be used with copper and
nickel-silver – the colors don’t match, but the warm gold of the
brazing rod creates a nice color contrast.
I use these brazing rods for decorative brazing on base metals.
When I use them as solder, I hammer out the rod somewhat (it is
brittle) and cut it up into little pieces with my aviation snips. I
use the same fluxes as with silver soldering.
Shameless plug: if you are a beginner, I’ll be teaching a course,
“Jewelrymaking and Metalworking,” at Ghost Ranch, near Abiquiu, New
Mexico, during the week of August 12-19, 2002. It covers the
basics, including hard-soldering, bezel-setting, decorative brazing,
photo-etching, and more. Their web site is <www.ghostranch.org>.