Ah, the sodium dichromate I have is part of the Kodak Tray Cleaner, which consists of sodium dichromate and sulphiric acid in an aqueous solution. (It is designed for cleaning trays in automatic processors, though I use it for reversal processing as a bleach). What I'm saying is that I'm not sure how the Sulphuric acid will affect the dichromate in the solution; the bleach is quite acidic so I don't know what would happen if it's mixed with, say, gum of casein for one of the alternative processies.