Shelf life of MCM100 : LUSENET : B&W Photo - Film & Processing : One Thread

Anyone tried MCM100 (From "Developer's Cookbook" by Bill Troop?

I have mixed it several times and the result is:

1. Mixed as per given formula, the unused developer changes to dark color and substantially weakens in strength after one week.

2. Left out the sodium phosphate tribasic for storage. The mixture darkens in color in two weeks time and looses strength.

3. Mixed catechol and ppd with sodium bisulfite for storege. The solution keeps about four weeks then darkens and looses strength.

In all above cases the solutions are unused after mixing and stored in glass-stoppered brown bottles to the brim and stored in fridge.

I preferred to mix at large quantities because of the toxicity of ppd in powdered form. Can anyone help me?

-- Peter Wong (, September 17, 2001


The problem in all cases is oxidation of the developing agents. The use of distilled water might help in reducing any dissolved oxygen in the solutions, as will less vigorous stirring during mixing. Also, Sodium Sulphite is more effective as an anti-oxidant than the Bisulphite.
You say you're using glass stoppered bottles. By this, I'm not sure whether you mean bottles with glass stoppers.
The standard tapered ground-glass laboratory stoppers aren't actually very good at excluding oxygen, unless they're greased with Apiazon or Silicone high-vaccuum grease. Try doing that, or changing to screw capped bottles with a decent neoprene gasket in them.

-- Pete Andrews (, September 17, 2001.

Very strange. I bought a kit of MCM100 from Photographers Formulary last year, mixed it, and it still looks good. I use capped brown bottles plus Tetenal Protectan antioxidation gas (butane/propane).

BUT, I haven't used the developer since february.

-- Patric (, September 17, 2001.

Thanks for the advice. I did use distilled water but stirring was always vigorous, I tried to prevent too long exposure in the mixing vessel. I used ground glass stoppers but I think I will switch to plastic capped ones. The use of bisulfite was intended to keep the solution from being acid, but maybe this is futile as ppd is alkaline itself.

But I would appreciate if Patric would advise whether the solution turns dark in color at all since February?

Thanks once again!

-- Peter Wong (, September 17, 2001.

I will take a closer look at the developer tomorrow when I go to the darkroom.

I don't think that you will get so much air in the solution when you're stirring - you're not whipping the solution.

You can use a tall form beaker to get a smaller surface that's exposed to air. Even better is to use an Erlenmeyer Flask and a magnetic stirrer. Then you can use a stopper on the flask. But that would be expensive. Using glass beads as stirrers is another option.

Sorry for my bad english.

Patric, Sweden.

-- Patric (, September 18, 2001.

I just checked the MCM-100 developer I have in my darkroom. Yes, it's amber in color now.

-- Patric (, September 19, 2001.

Patric, thanks. I forgot to mention that I mixed the chemicals with distilled water at 52 degree centigrade, which is quite warm for catechol (or ppd as well?). I wonder if this is also the temperature specified by the Formulary when they packaged MCM100? I have tried to mix ppd with cool water but it is just too difficult to dissolve.

-- Peter Wong (, September 21, 2001.

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