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LotusEsp
9-Mar-2017, 13:23
Whats the general consensus on the shelf life of flexicolor chemistry? (i.e. in practice, not from the spec sheet)

I'm specifically interested in decanted unmixed chemicals.
I'm storing in 1L airtight glass containers for:

developer replenisher
Bleach III replenisher
Fix replenisher
Final Rinse

any pointers would be gratefully received, I have a supplier for the chemistry, but its in bulk only, so want to make sure I am not paying $$$ to throw away 3/4 of it after a few months of non use.

chassis
9-Mar-2017, 15:43
Have a look at apug.org in the Color forum. Photo Engineer on that site is a former Kodak employee and provides lots of good information. User "bvy" also has some good contributions.

My sense is that bleach III and final rinse can be thought of lasting nearly indefinitely. Well kept developer has been claimed to last a year or more in oxygen impervious bottles such as glass or PET, with no air space in the vessel. Not sure about fix, I think it is similar in keeping qualities as standard black and white fixer. It eventually gets exhausted and a clue to this is cloudiness.

I am on my first set of flexicolor chemicals and love it so far.

rob4x5
10-Mar-2017, 13:18
chassis is right, contrary to what many believe, the developer can last many months, even years if stored as above, as my own experience shows.

chassis
11-Mar-2017, 05:19
Agree with rob. Another comment - avoiding chemical crossover extends useful life. A way to do this is to use a rinse step between each chemical bath. The primary C-41 process does not call for rinse steps between chemical baths. Minilab processors transport the film directly from bath to bath, and process monitoring tells the operator when to replenish or renew the chemicals.

In a DIY situation, rinse steps can be used between each chemical, to reduce dilution, maintain pH and avoid cross contamination. For bleach, fix and final rinse, to me the enemies are dilution and cross contamination. For developer, it is exhaustion or oxidation. The limits of developer life need to be observed in one's own process.

I use 1.5 minute water rinse steps between each chemical. The rinse water is held in gallon jugs at processing temperature in the tempering bath. I do not use a pre-soak of the film to remove the anti-halation layer.

Photo Engineer on APUG endorses rinse steps for DIY processing.

EdSawyer
11-Mar-2017, 10:03
Interstep rinse is not recommended for after dev, since it inadequately stops development irregularly across emulsion layers. Stick with kodak's recommendations. Second guessing by armchair engineers based on 'instincts' will just make the process more unreliable.

rob4x5
11-Mar-2017, 11:40
With C-41 one can go from the developer directly into the bleach, but a water rinse can and should be used only if a stop bath is used first, to more rapidly stop all development. I believe this is what Photo Engineer endorses.

chassis
11-Mar-2017, 19:14
Ed, have a read of Mr. Ron Mowrey's (aka "Photo Engineer") posts on APUG. He is a former Kodak engineer and endorses, or does not object to, interbath rinses. No instincts, just a career with Kodak in C-41.

Rob, yes this is the process I use, forgot to mention the stop bath. I use a very dilute acetic acid stop for 1.5 minutes at 100 deg F.

chassis
18-Mar-2017, 06:47
For those interested, below are the comments of Ron Mowrey, "Photo Engineer" from another site. The specific topic relates to a weak acetic acid stop bath, followed by a rinse bath before bleach. Applies to C-41 and RA-4 processes.

Quote:
People using rotary processes such as the Jobo were having problems with uneven streaks on negatives. The problem was caused by the fact that the bleach going in after the developer was not strongly acidic enough to stop development rapidly and so both Kodak and Fuji suggested addition of a 1 - 2% acetic acid stop after development. It is also recommended for the RA4 process where the bleach is even less acidic and the surface area is larger.

And so, the recommendation was adopted by those who wish, and with a rinse before the bleach, they also found that the bleach had an extended lifetime due to less developer contamination due to carryover.
End quote

http://www.apug.org/forum/index.php?threads/list-of-color-chemicals-and-where-to-get-them.79069/page-12#post-1083389

chassis
23-Mar-2017, 12:09
Forgot that I had this. This is from Ron Mowrey, aka "Photo Engineer" on APUG, a retired Kodak engineer. Rinse baths are identified after bleach and fix.

Mr. Mowrey mentions elsewhere that a dilute acetic acid stop after developer helps maintain bleach pH.

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