Chemical Reversal

Contributed by Ron Speirs -- rspeirs@oecmed.com

The reversal agent used in E-4 was quite nasty stuff (Tertiary butylamine borane). The agent used in Kodak E-6 is Dimethylamine borane, but I don't know much about it. Perhaps the reason that light reversal was recommend for do-it-yourselfers was that these chemicals were hazardous or hard to get.

I have been processing E-6 for more than 15 years. At first I bought the Kodak 1-gallon kit, but eventually found formulas for mixing my own. I stumbled on a very simple, workable reversal formula:

Prepare a stock solution of:

        Potassium Borohydride           0.1 g 
        Sodium Hydroxide                 10 g 
        Cold Water to make              100 ml

Use 12 mL of this stock per 1L of working solution. Use for 1 minute immediately preceeding the Color Developer. Don't wash between this reversal and the color developer. Use once and discard. I guess the reason that this chemical is not in official kits is that the working solution doesn't last.

This formula also works for reversing B&W film and paper, thus eliminating the need for light exposure during these processes.