What we--jewelers and metalsmiths- call soldering is, in fact
brazing. How do you define the difference?
I have fought this battle over and over again. I guess it is time
for another round.
First, I would like to inform all potential responders to what I am
going to say, that I am fully aware that a lot of authorities use the
term interchangeably, and all of them wrong. So do not bother citing
who said what.
The difference between brazing and soldering is in the function of
the solder. In brazing, the solder is an integral component of the
joint. The joint consist of joining surfaces, with solder filling the
space between them. Brazing is akin to welding, except that welding
uses the same material as the joint, but brazing uses a specially
In soldering, solder is used not to fill the space between joining
surfaces, but to trigger the process of diffusion between joining
surfaces. Solder can be considered a catalyst of the diffusion, which
is totally consumed during the process. After soldering is completed,
solder becomes chemically integrated into alloy comprising the joint.
To give a parallel from chemistry, it is like the difference between
solution and emulsion, with soldering been the former. The confusion
arises because some goldsmith use solder as a filler, and than the
process becomes brazing.