Caked Perceptol Part A

Sal Santamaura · Jul 17, 2006

I just mixed two liters (individually) of Perceptol from twenty or so boxes purchased a few years ago. Part A in one of the packets was caked. It dissolved with no problem, but I've not encountered this before and don't know if or how metol is affected. Can anyone comment from experience on whether Part A caking is predictive of reduced Perceptol activity? Thanks in advance.

pentaxuser · Jul 17, 2006

The current Perceptol instructions on its shelf life says that in its unopened powder form it's indefinite. This is a very bold statement which I'd imagine that Ilford, in stating this, would have taken into account any likely cakingand its effect.

I can't say what was the case for pre-Harman Perceptol but I'd be surprised if it has altered in its composition.

Sounds as if it should be OK but I am no chemist

pentaxuser

Gerald Koch · Jul 18, 2006

The A packet of two packet developers usually contains the developing agent(s) and a small amount of preservative. Unless the mixed developer is brown in color it is probably good. Try the leader test to see if it is still active,

Sparky · Jul 19, 2006

It caked - more than likely - because moisture got into the package. Probably through osmosis. But having a package that was already opened or if it had a hole in it, is a better explanation. It would make absolutely no difference whatsoever chemically speaking. That's just one microlitre less water to add when you mix it. You're probably just letting yourself get thrown off by the fact that it's clumping together. I doubt the perceptol itself, nor the film, would care.

Simon R Galley · Jul 19, 2006

Dear Sal,

It should be absolutely fine, caking should not be a problem as long as it is not rock when opened. If it is discoloured ( brownish ) do not use and return it to us and we will replace it.

In powder form it will last decades with no degadation of performance, no changes in formulation have occured.

Simon ILFORD Photo / HARMAN technology Limited

Sal Santamaura · Jul 19, 2006

Simon R Galley said:
Dear Sal,

It should be absolutely fine, caking should not be a problem as long as it is not rock when opened. If it is discoloured ( brownish ) do not use and return it to us and we will replace it.

In powder form it will last decades with no degadation of performance, no changes in formulation have occured.

Thanks Simon. I suspect a slightly less than perfect seal of the foil envelope permitted a small amount of moisture to enter. The contents, though "caked," were not hard and dissolved readily. Final developer solution is the usual Perceptol color -- almost clear. I'll now use it with confidence.

Caked Perceptol Part A

Sal Santamaura

pentaxuser

Gerald Koch

Sparky

Simon R Galley

Sal Santamaura

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