On Feb 28, 5:40*pm, DaveC wrote:
I want to solder a brass plumbing fitting to a stainless steel basin.

Possible? What is the proper solder & flux to use?

Soft solder (even the lead-free stuff) will stick if you
use an appropriate acid flux (look for 'Stainless Steel'
flux); same flux works for brass and for stainless,
it IS corrosive, don't get it on skin.

Silver solder is (just barely) possible, but risks melting
the brass.

Usually, a brass fitting just rests in some plumber's putty
or adhesive sealant. Why do you want solder?