Does leaving a print in fixer for more than the prescribed time exhaust the fixer faster?

[taxonomies]

Hi all,

A few weeks ago, a member at my local darkroom got a little upset because some people were leaving their prints in the fixer longer than the prescribed 2-3 minutes. He was claiming that doing so was “killing” the fixer.

From a pure chemistry standpoint, is this correct? My understanding is that the fixer is typically a salt solution that reacts with the remaining silver halide on the paper. The 2-3 minutes prescribed time most likely was determined to be the required time for 99.9...% or so of the remaining halides to be removed, and thus leaving the print in the fixer longer than necessary wouldn’t do much to the fixing solution since there would be little to no reagent (ie silver halides) remaining.

Now obviously in a shared workspace, people should be mindful of other people working and not leave their prints in the baths longer than needed and all that, but I’m just curious as to whether the grumpy dude was correct from a pure chemistry point of view.

Thanks!

 

[DavidJRobertson]

Wouldn't have thought so, for the same reason that you suppose.

 

[paul ron]

I wonder? but in a shared setting it can get quite crowded in the fixer if everyone jsut left their masterpieces in the fixer longer than it had to be there.

Curious, can a print be over fixed?

 

[removed account4]

i think that if a print was left in tthe fix too long it would reach a state of equilibrium, it woudn't kill the fix or the print
i have heard .. NEVER seen .. that a print left in fix too long will bleach the print ...
when i was in college students left prints ( rc and fb ) in the fixer for longer than the prescribed time ..
waaaaaay longer .. nothing happened to the print or the fix ...
i think the dude has nothing better to do than be cranky, unless of course
he has noticed problems with his own prints ... then he has reason ,,,

=== added later ===
if it is a shared darkroom maybe the person doesn't want his work thrashed about by others who might not
care for and treat his prints the way he wants them to be treated, so the shorter time in the fix, the better.
i remember gang darkrooms were a nightmare, not only in the fixing tray, but the rotary washer that students loved to
watch spin @ 50 MPH and damage every print in the cage.

 

[DavidJRobertson]

i have heard .. NEVER seen .. that a print left in fix too long will bleach the print ...

Not long ago I forgot to clear up and fell asleep with some test strips left in a tray of fixer. The next day there was no noticeable change to the print.

 

[Luckless]

If you are looking at the issue purely from a chemical reaction point of view, then is is fairly obvious that there would be a point where no more chemistry would be reacted.
However a possibly harder question to answer would be from a mechanical point of view:
- Can leaving prints in fixer for excessive lengths allow more unspent fixer to be carried over into the rinse bath to a point that is remotely noticeable? (Can some papers swell and soak up more over time kind of thing?)

 

[jimjm]

My main concern for leaving prints in fixer for extended periods of time is that it will take longer to effectively wash the paper, especially if you are planning to tone the print, or achieve archival quality.
According to Ilford's datasheet for MG FB IV paper: "There is no benefit in extending fixation beyond the recommended time; some loss of print quality might be seen when long fixing times are given due to image etching".

Also, leaving RC paper immersed in chemicals or wash water for longer than necessary is never recommended because it can cause edge penetration and print curl.

I don't think that leaving prints in the fixer will have any effect on the life of the fixer itself. Leaving chemicals sitting out in open trays is never a good idea due to exposure to air. I pour them back into the storage bottles when I'm finished printing for the night.

 

[MattKing]

If there are too many prints in a tray of fixer, it can really impede chemical flow and lead to uneven and incomplete fixing.
And by the way, prints in fixer need agitation too!

 

[mooseontheloose]

If there are too many prints in a tray of fixer, it can really impede chemical flow and lead to uneven and incomplete fixing.
And by the way, prints in fixer need agitation too!

+1

I've worked in my fair share of shared darkrooms and I've never understood why people do this. Maybe I just had good instructors who really emphasized the importance of agitation at all stages.

Regarding the OP's question - I can't answer from a chemistry standpoint, but I will admit that when I have worked with others I only do unimportant work like contact sheets or postcards, mostly because it's hard to gauge how many prints have been through the fix, and not being sure that it was mixed fresh the day I was using it.

 

[RalphLambrecht]

No because, the proper fixing time is the time to remove all unexposed and undeveloped silver but excessive fixing times will bleach highlights.

 

[taxonomies]

Thanks all for the replies!

Glad to see that my chemical intuition seems correct.

Interesting points about leaving a print in the fixer too long potentially affecting the print itself, although I imagine we'd have to be talking about 1 hour instead of 3 mins rather than 10 mins instead of 3.
Also interesting point about the washing etc.; fortunately at my darkroom the washing is handled by the staff.

And yes, great point about flow being impeded in a fixer tray full of prints! I also didn't know that agitating the fixer is recommended (I don't think I ever see anyone do it). The grumpy guy was partially right in his grumbling, in that in a shared workspace we should be mindful to not impede other people's workflows (but he should have been nicer about it, and his chemistry argument was wrong, hehe).

 

[MattKing]

If someone else is handling washing, I'd suggest a holding tray full of water and a rule that allows others to transfer prints into it after 10 minutes.
It would also be excellent etiquette for everyone to agree to agitate the fixer tray whenever nearby.

 

[Sirius Glass]

i think that if a print was left in tthe fix too long it would reach a state of equilibrium, it woudn't kill the fix or the print
i have heard .. NEVER seen .. that a print left in fix too long will bleach the print ...

I agree on both points.

=== added later ===
if it is a shared darkroom maybe the person doesn't want his work thrashed about by others who might not
care for and treat his prints the way he wants them to be treated, so the shorter time in the fix, the better.
i remember gang darkrooms were a nightmare, not only in the fixing tray, but the rotary washer that students loved to
watch spin @ 50 MPH and damage every print in the cage.

Good point.

My main concern for leaving prints in fixer for extended periods of time is that it will take longer to effectively wash the paper, especially if you are planning to tone the print, or achieve archival quality.
According to Ilford's datasheet for MG FB IV paper: "There is no benefit in extending fixation beyond the recommended time; some loss of print quality might be seen when long fixing times are given due to image etching".

Also, leaving RC paper immersed in chemicals or wash water for longer than necessary is never recommended because it can cause edge penetration and print curl.

I don't think that leaving prints in the fixer will have any effect on the life of the fixer itself. Leaving chemicals sitting out in open trays is never a good idea due to exposure to air. I pour them back into the storage bottles when I'm finished printing for the night.

+1

If there are too many prints in a tray of fixer, it can really impede chemical flow and lead to uneven and incomplete fixing.
And by the way, prints in fixer need agitation too!

+1

No because, the proper fixing time is the time to remove all unexposed and undeveloped silver but excessive fixing times will bleach highlights.

+1, but I have not noticed that.

 

[BMbikerider]

If a print is left in the fixer for too long, it can start to bleach out the highlights, although that length of time is unlikely to be reached in a single darkroom session.

 

[RalphLambrecht]

I wonder? but in a shared setting it can get quite crowded in the fixer if everyone jsut left their masterpieces in the fixer longer than it had to be there.

Curious, can a print be over fixed?

Yes, a print can be over fixed; an overfixed print suffers from bleached highlights and midtowns and the fixer will get harder torahs out in the final wash; strong and short fixing is recommended over weak and long fixing for complete fixing andease of washing.

 

[Arklatexian]

Hi all,

A few weeks ago, a member at my local darkroom got a little upset because some people were leaving their prints in the fixer longer than the prescribed 2-3 minutes. He was claiming that doing so was “killing” the fixer.

From a pure chemistry standpoint, is this correct? My understanding is that the fixer is typically a salt solution that reacts with the remaining silver halide on the paper. The 2-3 minutes prescribed time most likely was determined to be the required time for 99.9...% or so of the remaining halides to be removed, and thus leaving the print in the fixer longer than necessary wouldn’t do much to the fixing solution since there would be little to no reagent (ie silver halides) remaining.

Now obviously in a shared workspace, people should be mindful of other people working and not leave their prints in the baths longer than needed and all that, but I’m just curious as to whether the grumpy dude was correct from a pure chemistry point of view.

Thanks!

What fixer and who prescribed 3,4 minutes? I use sodium thiosulfate (hypo) fixer and fix fiber base prints for 10 minutes. I own prints that are 100 years old and were processed this way and they look new, except for the clothes styles that were in vogue at the time.. I think your reasoning is probably correct. and I would not consider my prints in my fixer as properly fixed at 3,5 minutes. I have read everything that I could find on fixing and have not found a really valid reason to change. If it is a "sin" to under or over fix, over is the lesser of the two.....Regards!

 

[Christiaan Phleger]

When doing wedding work over the years you could tell after the prints were toned exactly which had 'extended' fixing; the wedding dress would be bleached out and the toner would take a bit stronger. I learned to read the status of the fix by the smell; as soon as it started to hit a saturation point the odor would ever so slightly change. Fresh fix was a studio rule for clean consistent toning of the final prints.

As it is yes I have no idea why people let it sit a long time especially with test strips. RC paper fixes fast in Rapid style fixers. Move it along people!

 

[Ian Grant]

Prints left in the fixer too long will bleach, it happens very quickly with warm=tone papers particularly when developed for greater warmth. In a Sodium Thiosulphate based fixer this is slow but in an Ammonium Thiosulphate based rapid fixer it happens in minutes, with fresh fixer there's a noticeable bleaching of delicate highlight tons in about 5 minutes, there's also a shift in image colour.

Ian

 

[removed account4]

people tend to leave just fixed prints in a water tray after they fix, or between 1st and 2nd fix
WITHOUT actively changing water ( siphon, fill dump, overvlowing tray, tray with holes it it &c )
and static water with fixer saturated prints in it is the same as over fixing prints ... maybe a little less
because it is not a bath of fixer they are in, but it ends up being a fixer bath, especially if the same water
is used for multiple batches of prints without exchanging it.

 

[guangong]

Not sure about the answer to OP’s question, but leaving fiber based papers in fixer too long can result in fixer becoming imbedded within the fibers of the paper rather than just fixing the emulsion. This can make washing very, very difficult and cause deterioration of print as time goes by.

 

[Doremus Scudder]

Prints left in the fixer too long will bleach, it happens very quickly with warm=tone papers particularly when developed for greater warmth. In a Sodium Thiosulphate based fixer this is slow but in an Ammonium Thiosulphate based rapid fixer it happens in minutes, with fresh fixer there's a noticeable bleaching of delicate highlight tons in about 5 minutes, there's also a shift in image colour.

Ian

Exactly! While many "leave the print in the fixer overnight" and see no difference, overfixing will bleach prints and should be avoided (it's easy...).

Not sure about the answer to OP’s question, but leaving fiber based papers in fixer too long can result in fixer becoming imbedded within the fibers of the paper rather than just fixing the emulsion. This can make washing very, very difficult and cause deterioration of print as time goes by.

Fiber-base paper gets saturated with fixer after about 90 seconds in the fix. That's why the Ilford method uses strong fix and short (60 sec.) fixing times. However, many of us use longer times and simply wash longer. With extended wash times, fiber-base prints fixed for longer wash just as clean as those fixed for a shorter time. The cause of fixer by-products becoming stubbornly attached to the paper base is overused fixer. Using fresh fix or a two-bath fixing regime and not exceeding capacity for optimum-permanence processing (which are lower than the commonly-given capacities for "commercial standard") will ensure that prints can be adequately washed.

Best,

Doremus

 

[mshchem]

I follow the instructions. I use Kodak F6 two bath for fiber base. I do the Ilford 30 seconds in fresh strong rapid fixer for RC. I agitate constantly in fixer. If I am printing multiple sheets I don't over do it. I always use Kodak HCA, and I tone in KRST.
The old Kodak books from the 40's through the 80's are a font of wisdom . Ilford has really stepped up their website. Ilford has done their homework, any doubts that would be my default recommendation.

 

[RalphLambrecht]

I follow the instructions. I use Kodak F6 two bath for fiber base. I do the Ilford 30 seconds in fresh strong rapid fixer for RC. I agitate constantly in fixer. If I am printing multiple sheets I don't over do it. I always use Kodak HCA, and I tone in KRST.
The old Kodak books from the 40's through the 80's are a font of wisdom . Ilford has really stepped up their website. Ilford has done their homework, any doubts that would be my default recommendation.

I agree, both Kodak and Ilford offer very reliable process information on their sites.

 

[BMbikerider]

Yes as said before it will bleach out the highlights but more importantly if fibre based paper is left too long in the fixer it will extend the washing times to rid all the paper base of fixer chemicals even using something like 'wash-aid'. And no, it will not exhaust the fixer quicker because once the undeveloped emulsion is cleared of silver that is the end of the process, it cannot do anything else except start the bleach process which is very slow.........

 

[fdonadio]

Not long ago I forgot to clear up and fell asleep with some test strips left in a tray of fixer. The next day there was no noticeable change to the print.

You fell asleep in the darkroom?