In article .com,
says...
Using an ox/acet brazing tip and new,
prefluxed rod, clean material, I heated the parent material red hot,
almost to the point of puddling. I kept the secondary material nice and
red as well, and began adding the brass by laying the unmelted tip of
the rod into the inferno and applying heat to the rod so it would melt
and flow out across the hot material.

Did it work...hell no! As the torch melted the rod, it "spattered" and
popped, kinda blowing itself out onto the parent and secondary metal;
looked like a smoked up, ****ty stick weld that didn't penetrate.

Too much heat, not enough flux.

Get the parent metal hot enough to melt the filler, touch the filler to
the parent metal to melt it.

Fluxed rod is fine, but it's a lot easier to put some flux in the joint
ahead of time, too, so that the surface is ready for the filler to flow.
Plus, if the flux is well matched to your filler, you can tell the
parent metal is hot enough by the way the flux behaves.

(Of course, then there's GasFlux -- an endless supply of flux pre-mixed
with your acetylene, keeps the joint nice and clean even if you do
overheat it.)

There's a link to The Brazing Book from Handy & Harman on my web site,
it's a good intro to brazing, though it deals more with silver fillers
than brass.

--
is Joshua Putnam
http://www.phred.org/~josh/
Braze your own bicycle frames. See
http://www.phred.org/~josh/build/build.html