Fixer shelf-life

[jameswilgeroth]

Developers tell you how long they last, stop baths come with indicator which tells you when they are bad, but fixers are a bit different.

Is there a general rule of thumb for how long a fixer will last once open (say 1 ltr bottle)?

Also....
How long will unopened fixer remain good?

I understand that a clearing test might solve all of the answers above, but a little built-in knowledge is always useful.

Anybody have any trade secrets or tips?



Thanks

 

[Early]

I don't know the shelf life of fixer, but I always dumped mine regardless when the sulfur, or whatever it was, dropped out. You can test it, though. to see how long it takes to clear a strip of film.

 

[Hamtastic]

Is there a general rule of thumb for how long a fixer will last once open (say 1 ltr bottle)?

Depends how much air and how long it's exposed. Depends on how well your stop bath is working. The more developer in the fixer the sooner it goes. I would consult the tech pub from the manufacturer for recommended capacity.

A clearing test works. A bottle of hypo check is cheap and reliable, and lasts a long time (you only use a drop or two at a time).

Edwal | Hypo Check (Liquid) - 3/4 Oz. | EDHC3/4 | B&H Photo Video

 

[chris]

When the fix is first made up cut a small piece of film, drop it in the fix and note the time to clear.
Do this each time the fix is used and when the clearing time has doubled it has reached the end of its useful life.
If you are getting a black precipitate in the fix then it should be discarded. The precipitate is silver, not sulphur. The silver dissolved in the fix can be recovered but you need to be processing huge quantities of film to make this worthwhile. When I was an industrial radiographer we used to sell the spent fix to a recovery company. We would typically be processing 100 to 200 4" x 14" films per day and would save the spent fix over a two month period to accummulate enough to make it worth collecting and processing.

 

[jms12886]