TF-5 Tray Life?

[NortheastPhotographic]

I had a working solution of TF-5 die after about 7 or 8 days in a bottle (attached to a Phototherm Super Sidekick). This was surprising because it was well within roll capacity.

Does exposure to oxygen kill TF-5 early, or does it have a short tray life?

 

[Doremus Scudder]

Yes, fixer will die because of oxidation.

It's too bad that the TF-5 data sheet doesn't have more detailed information on the life of the working solution in trays, half-full bottles, etc. What they do say is:

"STORING TF-5
All photographic solutions should be used as soon as possible. TF-5 stock solution should not be kept for more than 12 months. All fixers should be kept away from high heat (over 85° F), as this will shorten the shelf life. If TF-5 is to be kept for some weeks after opening, it should be placed in smaller bottles filled to the top, with tight caps."

My added emphasis indicates to me that TF-5 may be more prone to oxidation than other fixers. Too bad Ron Mowrey is no longer with us to answer your question and provide some more information.

FWIW, Ilford states that their rapid fixer working solutions will last only 7 days in an open tray and only one month in a half-full bottle. TF-5 may be less than that.

Best,

Doremus

 

[Bob Carnie]

Doremus what are your thoughts of fixer left in tray ? Sometimes I barely use the fix and need it for next day.. putting plastic over the tray will help???

 

[Doremus Scudder]

Hi Bob,

I use Ilford Rapid Fixer or Hypam normally and just leave bath one out, sometimes for 3-5 days, in a tray without a cover of any sort. That said, the second fix is always mixed fresh and prints to be toned are run through it right away, so any decrease in fixer activity of bath one from oxidation would be compensated for with bath two. Bath two then gets moved to the first fix position, where it stays out for a few days.

If you're using TF-5 and are worried about oxidation killing it, you could either bottle it (full bottle) or cover it with Saran Wrap. I've read that the Saran Wrap brand is different from most other plastic wraps and is less permeable to oxygen, making it a better choice for covering chemicals prone to oxidation than others.

When I have developer that has only had a few prints through it that I want to save for the next day, I'll bottle it if it's only one or two liters, since I can easily pour it into a bottle from the tray. If I'm printing larger, I'll use Saran Wrap, since pouring from a large tray into two or more bottles is just a PITA I've also just floated another tray of the same size on top of the developer (nesting trays are nice for this) to cover it and reduce oxidation. Any of those methods would work for fixer too.

Best,

Doremus

 

[Rudeofus]

Ron once told me, that he left an open tray with TF-5 in his garage, forgot about it, the fixer dried out completely. He then filled the tray with water and the fixer worked again like fresh. His report matches my experience with neutral fixer. I can store my home brew neutral fixer in random bottles for months, use it weekly to process a few sheets, and it just keeps going. Yes, oxidation will kill all fixers eventually, but in neutral fixers oxidation is very slow.

For these reasons I am VERY surprised to hear about TF-5 going bad like this. The only explanation I have is that either during processing some incompatible chemistry was carried into your fixer, or that some vapors got in. Was there an Acetic Acid based stop bath nearby?

 

[iandvaag]

Too bad Ron Mowrey is no longer with us to answer your question and provide some more information.

In this case you can actually hear Ron tell the story Rudi mentioned in this episode of Inside Analog Photo Radio. Watch from 12:49 to 14:20.

His expectation is 3 months in an open tray, conservatively.

 

[Doremus Scudder]

What Rudi and iandvaag report would tend to contradict the very conservative estimations of lifespan and caveats to store TF-5 in full bottles only from the Formulary data sheet. This latter is what I was basing my surmises on.

In this case, however, I rather believe Rudi and iandvaag (and Ron through their reports), meaning that the Formulary data sheet is likely overly conservative. So, I don't really have a good idea either of why the OP's batch of TF-5 went bad so quickly.

Hope I didn't promulgate any false information.

Best,

Doremus