GLYCIN AGING ISSUE: LONG ANSWER
Glycin turns color as it ages. But after 35 years of use, I've yet to be concerned over it. I never heard of ANY issue about 'short life span' before the Internet. Probably because I only talked about it with guys that used it every day.
Here are some ideas:
1. Order what you think you'll use in 6 months or a year. I go with a year's supply, but if you're concerned, go with 6 months.
2. Test before important jobs. How long does it take to contact print a step wedge to a piece of film, and toss into a tank ? I only use a densitometer when I'm testing ( I should say, perhaps, Confirming, or Affirming ) or to monitor the process with regular work. I don't have problems with densities drifting, but I like that 'occular proof' that encourages me "Believe in What Is Happening" instead of "Worrying About What Might Go Wrong".
NOTE: on the last roll of a shoot, there are always a few unexposed frames. I use them for a Zone VIII test. In that way, job I shoot is a precise confirmation of the process. if I have any doubts about the exposure of the job, that's a test roll that I develop in strips. So, I guess, it really doesn't matter if the developer is losing it's potency or not: I'd catch it.
I pretty much shoot every day. If I shot every 6 months, there's NO question that I'd order fresh film and chemistry for the event. A quick test would give me all I needed to know. Why order fresh ? Because it would press me to test and not be lazy. I don't worry because I know what's going on.
3. Mix fresh. Why are we even worried about keeping qualities ? Mix up a small amount of 130 before a printing session and use it up. I go through a gallon in a week, so I mix a gallon at a time. Monday morning is Chemistry Day. I throw out developer at the end of the day's printing. I can't believe ANYBODY would save used developer. ( Ripening is another issue, and beyond this conversation ! )
4. FX2, in two parts, lasts pretty much forever. How long ? I have no idea. I've used some that was a year old (after Confirming its activity) and it was fine. But I mix up a working solution the night before i intend to use it, and it's all gone in a week.
In short:
- glycin seems to last a long time in solution, and nothing in my experience indicates that it doesn't.
-- dry glycin darkens slowly over time but I've never seen a correlation between color and potency
--- normal photographic precaution wil detect any normal loss of potency - regardless of materials - and there is no need to worry.
