Any other flux suggestions to try until I find my favorite?
I use Cupronil exclusively and have done so for about 15 years, both
with silver and gold. Early on I tried both paste flux and Batterns
but didn't like either.
I didn't know this when I first tried Cupronil but it turns out that
it's manufactured by a long-time Orchidian -- Lee Epperson. That's a
nice bonus :-).