On Jan 31, 3:55*pm, Louis Ohland wrote:
* *Folks, I'd like to silver solder up an extractor for a High Wall.
What kind of flux do I need?

Usually the same place you bought the filler will have the
corresponding flux. Some fluxes have other stuff than borax in them,
some fillers need that stuff to wick into the joint. So the real
answer is that it depends. For that type of work, you can't beat
silver braze/flux paste, expensive, but will give a good joint all the
time without disturbing the clamped parts. Brownell's has it. Takes
longer to purge the hoses on the O/A rig than to do the joint. A talc
stick is also handy to keep the braze from wicking where you don't
want it.

Stan