Borax

PDR · 1168328. Fri Jan 08, 2016 6:17 pm

I was slightly surprised that the discussion of uses for borax overlooked the engineering one - borax is the primary constituent of the fluxes used in brazing and silver-soldering brass, bronze, copper, steel and stainless steel. In fact plain borax (the stuff they used to sell as a laundry product in supermarkets before the elfin safety nuts objected) just mixed into a paste with water can be used as a very effective flux - the commercial versions just have additives to improve the flow characteristics and melting properties (although silver-soldering stainless with ordinary borax can be a bit difficult).

Borax has also been used instead of mercury in gold extraction.

PDR