Response to Rodinal with Ascorbate - what am I doing wrong???

Ryuji, I think sometimes that your theories keep you from having a lot of fun. I seem to remember that the pH of ascorbic acid solution is about 3. What happens when you use bicarbonate to neutralize it depends on how much water you dissolve it in and how cold it is. The CO2 that makes the fizz will not be there if you use enough water. This is not good. Carbonic acid is weak enough so that we can drink it, but one molecule of it still neutralizes 2 molecules of NaOH. I get good results when I mix the ascorbic acid powder and baking soda in a very small alount of warm water. This mixture is not harmful, so you can taste it with the tip of your tongue to see if it still has any sour or tangy taste. Sodium ascorbate is very near neutral pH in solutions as high as 10%. The amount you put in Rodinal is .2 % of the working solution. If you increase the amount of baking soda beyond that needed for neutralizing the ascorbic acid, you begin to form a hydroxide-bicarbonate buffer solution. The 8 grams or so swamped the hydroxide in the Rodinal, which is actually very small in a 2% Rodinal solution. Now you have a developer with sparse amounts of developing agents and a low pH. I am not trying to promote ascorbatized Rodinal. It does give finer grain than plain Rodinal while keeping some of the other characteristics, but I would and do use a little metol or phenidone in place of it most of the time.

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