[Bill Douglas]

I remember in welding night class there is some acid sort of stuff that you put on stainless steel welds and overnight it dissolves bits of carbon and black soot out of welds.

The reason I ask is I've bought a nice stainless steel S&W snubbie revolver that has a couple of tiny areas of corrosion that I'd like to dissolve the black spots out of then put renaissance wax on to fill the "pores".

Do any of you welding guys know what it may be - thanks.