Hi Kat, Bruce, and gang,
I don't recall anyone here claiming to be an "expert"... even if
some of them are. We're all just trying to help each other.
For all practical purposes, you can't solder aluminum for use
with jewelry. It won't stand up to the use/abuse, even if you do
get it soldered using the proper solder and flux.
I assume, based on the nature of this forum, that he is talking
about jewelry... he didn't state otherwise. Soft solder is not
generally acceptable for jewelry use. You also did not
address whether this magical flux and solder would allow the
joining of aluminum and silver, which was the problem as
presented. Soldering aluminum gutters or radiators is one
thing... making jewelry, I find, is something much different.
NOT an expert nor a professional,
Charlotte, NC (USA)