Pyrocat M - Brown powder residue?

BarryWilkinson said:

Two months ago I mixed up my first batch of Pyrocat M from raw chemicals. Most of the chemicals had been around for a while.

The first sheets I developed in the chemicals were very good. However, after use I put the brown glass bottles in a fridge as my darkroom as it gets very hot.

I developed some more sheets 3 weeks later and found a brown powder residue on the washed film and in the bottom of the processing tray after they were dry.

I have assumed that the chemicals have gone bad and will mix up a fresh batch with new chemicals. Has anyone else exepirienced this residue. I am a little concerned that if this re-occurs I will destroy some important negs.

Barry

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Tom Hoskinson said:

Were the solutions you put into the refrigerator the stock solutions? Were they the residual working developer?

In either case, as the solution temperatures decrease, the least soluble chemicals will tend to precipitate out of solution.

Recommendations:
1. Don't store the used working developer, use it as a one-shot, then dump it.
2. Store the stock solutions in completely filled brown glass bottles at 20 deg. C (or a bit higher).

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