TF-3 Fixer working solution shelf life

[MurrayMinchin]

Anyone know the shelf life of working solution TF-3 diluted 1:4? (I keep mine in mylar wine bags...no oxygen, no light).

I ask this because I'm working very "sporadically" these days, what with the full time job and 3 1/2 year old child and all...

I've been tossing it after 2 months no matter how many prints get made (I use the 2 bath method)...do you think that could be safely increased? I didn't get TF-3 via the Darkroom Cookbook so I don't have the original information.

Thanks,

Murray

 

[Tom Hoskinson]

Suzuki gives excellent advice in this regard - check out his neutral fixer posting in the APUG Chemical Recipes Section. Basically, you need to periodically test your fixer.

 

[fhovie]

My fixer never goes over two months and it never dies from shelf wear. I get about 17 8x10 (rolls of film) per liter of 1:4 for film. I get a great deal more 8x10 fiber prints per liter - I'll bet I get nearly 40 8x10 sheets per liter 1:4 also.

I always test the fixer after a printing session - It should not take over 60 seconds to clear a piece of film - usually 40 seconds.

 

[jim appleyard]

I never bothered to keep track; never bothered to count the number of rolls of film or number of prints that I put thru the fix. I always had a bottle of Edwal Hypo Check handy and added a drop to the fix before each session.

Another way to tell is to drop the leader of the film into the fix. As said above, if it clears in about a minute, you're good to go.

 

[Photo Engineer]

Unused fixers usually go bad by the reation of acid with hypo and oxidation of hypo and sulfite. The neutral and alkalline fixes are much more stable for this reason. From pH 6 - 8, a fix is considerably more stable than a fix at pH 4.5 such as Kodak Rapid Liquid Fix.

Used fixers can be tested for exhaustion fairly easily by a test solution of Potassium Iodide added to a sample of the fix. If the fix is bad, a heavy yellow precipitate forms (Silver Iodide) due to the excess of silver in the hypo. If it is good, either no precipitate or a faint yellow cloudiness forms.

This test solution is available from many photo shops. (Like the Edwal Hypo Check - Jim has it all down pat.)

PE

 

[MurrayMinchin]

Thanks guys.

I always test the fixer after a printing session - It should not take over 60 seconds to clear a piece of film - usually 40 seconds.

I think I'll run with this for a while. With fresh fix the clearing time is 30 seconds. I'll see how long (with my sporadic schedule) it takes to get to 50 seconds...then I'll probably get nervous and dump it!

Thanks again,

Murray

 

[Tom Hoskinson]

I always test the fixer after a printing session - It should not take over 60 seconds to clear a piece of film - usually 40 seconds.

That depends on the fixer. For example, my recent tests (see the APUG thread) with freshly mixed Fine Arts T grain film fixer showed clearing times of 3 minutes, 20 seconds for TMAX 400 and 2 minutes 30 seconds for efke R100. These times are entirely consistent with the manufacturer's recommended fixing times.

 

[dancqu]

Unused fixers usually go bad by the reation of acid with hypo
and oxidation of hypo and sulfite. The neutral and alkalline fixes
are much more stable for this reason ....
.... a test solution of Potassium Iodide added to a sample of the fix.
If the fix is bad, a heavy yellow precipitate forms (Silver Iodide)
due to the excess of silver in the hypo.

A heavy yellow precipitate? The fix is very bad and that's for
quick and dirty. That test will not work for archival. The very dilute,
one-shot, unadulterated fixers I use, produce when near fully spent
a barely perceptable white haze.

Working strength S. Thiosulfate has a ph of 6.8 to 7.0 and
the same in P. Formulary's A. Thiosulfate has a ph of 7.6 +/-.
S. or A. Thio., nothing is added to make a working strength
fixer save water. Dan