Hi all, i've completed my preheater and drip pan. Now I have to solder the corners of my drip pan. The pan is made out of light Stainless. I've been looking at fluxes(which I can't find anywhere for stainless)and have thought of making my own out of Borax,potash and table salt. Has anyone had any luck or thoughts on Soldering stainless? also copper to stainless?

Any thoughts would be greatly appreciated.