I discovered some chemicals that I have forgotten about. The rapid fixes does not seem to have the exp date but photoflow and hypo clearing agent do, and they are out.
What would be the effect of these expired chemicals on the dev? Are they still ok to use?
HCA. Yours is expired since 6 months. The powder will still be 100% OK in 10 years.
Photo-Flo. I still use the same bottle of Photo-Flo 600 since 40 years.
Rapid fixer. Ironically, the one without an expiration date is the one you migh be worried about. Peek through the bottle opening: do you see a yellow sulphur deposit? In doubt, prepare some 1+4 dilution and try fixing a clip from a regular emulsion (400TX, FP4,...). Should clear in 25sec. 1+9 should clear film clip in ~1min. If it passes that test, it should be OK. I've had some Tetenal fixer with the yellow deposit that would nevertheless clear a film clip in 25sec. Just to be safe, I'll use it for paper.
Bernard_L is right.
If the sulfur has precipitated out of solution, leaving yellow mud in the bottom of the bottle, it's no good. Just throw it out.
KHCA is a mixture of sodium sulfite and sodium bisulfite; the powder should be good forever.
PF-200 stock solution should be good indefinitely; mixed to working strength, a week at most. Algae will grow in the working solution- when I ran a sink line in a custom lab, the PF tank was changed weekly for this reason. Not a problem if you mix a small amount every time you process film. (PF-600 was made for huge commercial film processors and is merely a 3x stronger formulation.)
Mark -- Photo-Flo 600 is a different beast (and more toxic) than Photo-Flo 200. Photo-Flo 2100 is the same chemically as Photo-Flo 200.
"Landscapes exist in the material world yet soar in the realms of the spirit..." Tsung Ping, 5th Century China
There is some controversy about that, some say that sulphured out fixer should not be used because sulphur may contaminate the emulsion, so "LE500 is not fulfilled", others say that this is not a hazard at all because elementary sulphur is just insoluble in water.Originally Posted by Mark Sampson
... and anyway fixer chem concentrations vary a lot more while it is exhauted by normal usage.
I was told that this is because some O2 entered because of marginal plastic bottle porousity, but that it can be filtered out and the fixer used if not insane amounts of precipitation. I had a 15 years old bottle that passed perfectly the clip test, I filtered out the yellow thing and I used it in the first bath of the two bath fixing I do. Negatives are 4 years old now and I see nothing different.
Fixer is fairly cheap. Why mess with an old bottle of fixer if it has (partly) sulfured out?
Well, in part to not generate more waste than necessary, but on any doubt better to throw it, I agree. Anyway IMHO it's always good to know when chem is ok or not beyond expiration, and why. Somewhat it allows a better understanding about how products in the shelf should be managed, and that leads to better practices to keep chem ok.
We could be throwing Photoflo bottles each time it was expired, but we learned it's not necessary...
Vaughn, 20 years in the labs at Kodak never told me that about Photo-Flo. Live and learn...
Sulfurized fixer simply won't fix your film. Don't risk your pictures, time and effort trying to use it. Although some people happily drink sour milk and eat moldy bread (not me though). Fresh is best!
Ok, but how much sulphur we need to throw it? One spec? 5 grs? 2" in the bottom?
Pere, if there's any 'mud' at the bottom of the fixer bottle, get rid of it. Sadly, I have too much experience with this issue. Imagine cleaning up a neglected 42" Kreonite roller-transport RA-4 print processor when the bleach-fix has sulfurized. I've done that more than once... So fresh fixer is just a "better safe than sorry issue", at least for me.
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