At 03:55 PM 6/15/2012, neil n wrote:
>And speaking of DIY flux, one can use Borax for silver brazing flux!

Ordinary powdered flux for "bronze" brazing is 
largely borax, but silver-brazing flux is a lot more complex (and nasty):

>Silver-brazing fluxes contain boric acid and 
>potassium borates, combined with complex 
>potassium fluoborate and fluoride compounds. 
>Fluorides, up to 40 percent in flux content, 
>give these fluxes their characteristically low 
>melting points, 1,050� F. and high activity for 
>dissolving metal oxides. Silver-brazing fluxes 
>that contain elemental boron offer improved 
>protection on carbides and on materials that 
>form refractory oxides such as chromium, nickel, and cobalt.

;-)
d