Black Sediment In Fixer With Flakes

MattKing said:

Same applies to me, in my decades of carefully re-using film fixer - almost exclusively rapid fixer.

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good for you!
What I'm trying to convey is the concept that using fixer one shot costs way less than re-shooting (whenever possible) the film.
All in all the total cost of developing+fixing is paltry with respect of the time spent, the cost of travel, to shoot a roll (or more) of film.
Is it worthwhile to risk?
No. imho.

Alessandro Serrao said:

You should add "in my opinion"...

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To whom the shoe fits...
Having said that, I virtually always use my fixer one-shot, at 1+10 dilution. It's not too wasteful and it definitely is very consistent and reliable. Just my personal workflow of course...

braxus said:

Its weird because even the most recent films I did look completely clear with no fog. Oh well. I'll try to mix up a fresh batch. I didnt think I did that many films in this fixer batch, though it has been sitting for quite some many months inside a capped/ sealed 1L container.

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Fixer goes bad with age (oxidation) as well as exhausts with use (by-product build up that inhibits fixation). That's why it's a good idea to do a clip test on older fixer even if it hasn't been used to capacity.

Film can look clear and still not be adequately fixed. Film should be fixed for a minimum of twice the clearing time. So, if your film has just barely cleared, there are still insoluble thiosulfate compounds left in the emulsion that can degrade and discolor over time. Hence the clearing-time test.

Doremus

Alessandro Serrao said:

good for you!
What I'm trying to convey is the concept that using fixer one shot costs way less than re-shooting (whenever possible) the film.
All in all the total cost of developing+fixing is paltry with respect of the time spent, the cost of travel, to shoot a roll (or more) of film.
Is it worthwhile to risk?
No. imho.

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It's not difficult at all to keep track of the number of rolls or sheets you've run through a given amount of fixer and discard the fixer when it reaches capacity. If you want to be conservative, you can discard it before it reaches capacity.

Similarly, it's not hard to do a clearing test to see if older fixer is still active. That and checking for precipitate and/or flakes in suspension in the concentrate ensures that one is not using fixer that has oxidized and lost activity.

Manufacturers publish rather conservative throughput capacities for their fixer; they have to ensure adequate fixation in the worst-case scenario (which would be fixing unexposed film). Using the manufacturers' capacities and storage recommendations is equally efficient and a lot more economical than using fixer one-shot if you can reuse the fixer within it's effective shelf-life.

That said, I try to use fixer one-session. I'll save up film till I have a larger batch just so I don't have to save fixer for later. And, of course, if you end up saving used fixer for longer than the shelf life, you have to toss it anyway.

The above relates to film, of course. No one would think of tossing an 8x10 tray full of fixer after only one print When printing, one needs to keep track of throughput and shelf life as well though, especially with fiber-base paper.

Best,

Doremus

Doremus Scudder said:

No one would think of tossing an 8x10 tray full of fixer after only one print

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Prints are second generation and if you mess up with something you can always reprint.
Once the film is ruined it's ruined and that's all.

Alessandro Serrao said:

good for you!
What I'm trying to convey is the concept that using fixer one shot costs way less than re-shooting (whenever possible) the film.
All in all the total cost of developing+fixing is paltry with respect of the time spent, the cost of travel, to shoot a roll (or more) of film.
Is it worthwhile to risk?
No. imho.

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Absolutely.... I agree with you. And 3oz of fixer to insure clean film won't break the bank....

This is nothing to argue about. Using fixer 1-shot is not a big deal. It ensures proper results. It doesn't invalidate using fixer for numerous rolls. It's simply a different practice. There's no waste. Ultimately, it all goes down the drain.

Alessandro Serrao said:

Of course Ivo, in a reversal setting the fixer is much more preserved in terms of capacity since it has to fix way less that a negative film.

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That said, there appears plenty to fix as the clearing time increases a tad towards the end of 10 rolls.
Especially when doing Delta 100

I see this in my fixer as well (film only). I use TF-5 in a 2 bath scheme. For the first time, I now store in Nalgene bottles (Kodak chem plastic bottles for years), and it has been doing this ever since I started using these bottles.
I use 500ml bottles, #1 bath, and @2 bath. The stock fixer I keep in a larger bottle.
I check the #1 fixer about every 5 rolls with clip test, clears in about 15 - 20- seconds. What is interesting is that both bottles have this black, very fine "silt" but it doesn't seem to make any difference.
When I change out the fixer (I just do both bottles each time), it's nearly impossible to get the black stain out of the Nalgene, so the new batches seem to develop it almost right away.
Doesn't seem to affect anything, but bothers me.

George Collier said:

What is interesting is that both bottles have this black, very fine "silt" but it doesn't seem to make any difference.

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That's generally just silver precipitating out of the fixer. The main concern with this is that these silver particles can embed themselves in the gelatin emulsion where washing won't reliably remove them. They end up as tiny little spots in the prints or scans. Filtering the used fixer helps. Or use the fixer one-shot, of course.

Let's do some math.
How much does it cost a bottle of fixer?
In the USA a bottle (32oz concentrate - the 1.2 gal concentrate is even more cheap per liter ) of Kodak Rapid fixer costs 15$.
It makes 1 gal of ready to use solution.
An Ap tank requires 300ml of solution for 1 roll of 35mm (for steel tanks it's even cheaper).
1 gal equals to 3,8 liters, that is about 12 35mm films.
So 15$ divided 12 equals 1,25 dollar per film fixed with the assurance that:

1) the film will be fixed properly;
2) the film will not get ruined irreversibly.

Alessandro Serrao said:

2) the film will not get ruined irreversibly.

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Insufficient fixing is virtually always 'fixable' (hah) by simply re-fixing the film in fresh fixer.

Alessandro Serrao said:

equals 1,25 dollar per film fixed with the assurance that:

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...and that'd quite precisely double the reversal expenses per film in my case

Alessandro Serrao said:

Let's do some math.
How much does it cost a bottle of fixer?
In the USA a bottle (32oz concentrate - the 1.2 gal concentrate is even more cheap per liter ) of Kodak Rapid fixer costs 15$.
It makes 1 gal of ready to use solution.
An Ap tank requires 300ml of solution for 1 roll of 35mm (for steel tanks it's even cheaper).
1 gal equals to 3,8 liters, that is about 12 35mm films.
So 15$ divided 12 equals 1,25 dollar per film fixed with the assurance that:

1) the film will be fixed properly;
2) the film will not get ruined irreversibly.

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I used film fixer one-shot for a number of years until disposal of used fixer became an issue in my county. The silver has been determined to be hazardous to marine wildlife. We are no longer permitted to pour it down the drain. I have to take it to the hazardous waste disposal site, which is a 15 mile drive, or dry it with cat litter for disposal with solid waste. I develop mostly 12-exposure bulk loaded rolls of 35mm B&W film. Clip tests show that it takes at least 20 rolls of film to double the clearing time with one quart of working strength rapid fixer, which is when I replace it. So my choice is to legally dispose of either one quart or roughly five gallons of used fixer. I've been using the one quart approach for the past four years with absolutely no fixer related issues.

Sanug said:

This is wasting fixer. Not needed and not a good idea.

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If done in a two-bath fixing sequence, it's well worth it and does not waste any fixer; it is a recommended archival processing method.

koraks said:

Insufficient fixing is virtually always 'fixable' (hah) by simply re-fixing the film in fresh fixer.

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a spoiled fixer will riun the film irreversibly, for example embedding some colloidal sulfur in it, or some ag flakes...
It is also to take into consideration how many rolls one develops in a 3-4-5 months timeframe (the time the diluited fixer gets spoiled). I personally shoot very little in a year and if I had to reuse the fixer, the concetrated bottle would get spoiled before I can use it all up...

Alessandro Serrao said:

1,25 dollar per film fixed

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That, for most people, is a waste of money. Just accept that.

You can easily reuse fixer until it wears out. Even using it for 2 rolls would cut your expense in half. And there's no way you can't use it for a second roll.

In the meantime, this is a pointless discussion. Do what you want. And don't bother anyone else who is getting along fine doing what they want.

Don_ih said:

That, for most people, is a waste of money. Just accept that.

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In real life a real waste of money is another thing...

Don_ih said:

And don't bother anyone else

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Bother?
Really I don't give a ... about it.
But considering the OP I have doubts that "anyone else who is getting along fine doing what they want."

Alessandro Serrao said:

I have doubts that "anyone else who is getting along fine doing what they want."

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Almost everyone reuses fixer and doesn't end up with much unfixed film. Yes, it happens sometimes. But you can refix those negatives years later and they clear - as long as they stay mostly out of the sun (and most negatives don't spend much time in the sun).

Regardless - who really cares? It's an insignificant chemical.

JerseyDoug said:

The silver has been determined to be hazardous to marine wildlife.

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Unless you're running a film-dev lab in the mid-90s, you can't have a single little bit of impact on marine life with what you dump down the drain.

Don_ih said:

Almost everyone reuses fixer and doesn't end up with much unfixed film. Yes, it happens sometimes. But you can refix those negatives years later and they clear - as long as they stay mostly out of the sun (and most negatives don't spend much time in the sun).

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I agree but there are other types of damage to the emulsion, damage done by a spent fixer other than underfixed film. Those types of damage I was addressing to (mainly embedded colloidal sulfur and various silver speckles) when I suggest to use the fixer one-shot.
And, no, sorry no, you can't refix an underfixed film years later WITHOUT expecting some kind of image damage...

Alessandro Serrao said:

a spoiled fixer will riun the film irreversibly, for example embedding some colloidal sulfur in it, or some ag flakes...

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I think most people are sane enough not to use a fixer that looks like the one OP posted. If it's dark-colored and has crud floating around in it...better not.
The typical scenario we see from time to time is ostensibly fine, but overused fixer that still looks clear and good to go, leaving a roll of partially fixed film. In that scenario, re-fixing solves the problem.

Alessandro Serrao said:

And, no, sorry no, you can't refix an underfixed film years later WITHOUT expecting some kind of image damage.

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Actually, I've done it. A year or so ago, I was looking through one of my negative binders and saw that a roll of film from 2015 was underfixed. So I put it in fixer and it's fine. It doesn't really undergo any change unless it's exposed to a lot of light (or a little light over a long time).

Don,
Underfixed film often develops stains, which cannot be fixed out later. Underfixing can also result in the loss of image silver, as it degrades when exposed to contaminants. That and the danger of getting flakes of sulfur or silver on your film should be enough to warrant careful monitoring of fixer capacities, activity and shelf-life (especially with fixer stored for a longer time) in order to avoid underfixing in the first place.

Alessandro,
Fixer for film remains active enough to do a thorough job of fixation until it reaches a dissolved silver content of 8-10 g/liter. That translates to 24 8x10 sheets or 24 rolls of film per liter. If you had 24 36-exposure rolls to develop, you could mix up a liter of fixer and use it for the entire batch. That would be most economical. So, even saving up a few rolls and fixing one batch would be lots more economical than using your fixer one-shot. 300 ml is 30% of a liter - 30% of 24 rolls is seven rolls and a bit more. You could cut your fixer costs by seven-fold just by saving up seven rolls of film, then mixing 300ml of fresh fixer to use in a session for all seven rolls. Of course, you'd have to keep an eye on fixing time, which increases as the fixer is used, or, like I do, simply fix for 4x the clearing time to begin with for the entire batch. Heck, you could be conservative and just do four or five rolls per 300ml batch of fixer and still cut your fixer costs significantly.

That said, using fixer one-shot does guarantee adequate fixation; it's just a waste of chemicals and cash. From your posts, I surmise that you aren't interested in saving money and that it's worth spending five or seven times what is needed in order to have peace of mind that your film is well-fixed. That's fine... but please realize that your recommendation to others to adopt a one-shot fixation regime for film is not scientifically sound.

One thing that I've done in the past to not waste fixer when I was processing very little film and at greater intervals, was to use Ilford Rapid fixer one-batch or one-shot (depending on the amount of film I had to process) at the 1+9 dilution instead of the stronger 1+4 dilution. I checked this practice with the Ilford technical representative, who confirmed that, yes fixation will be fine as long as the fixing time were adjusted accordingly (clearing-time test) and the capacity was not exceeded (which would not happen one-shot), since the fixer would exhaust more rapidly fixing film at the higher dilution (not due to by-product build-up, but rather using up enough of the active ingredient that the fixer became to weak to do its job).

Best practices for fixation has been discussed ad nauseum here and shouldn't really be a bone of contention any more. If one wants to optimize expense and adequate fixation, the research is clear: fix to capacity and no more and keep an eye on fixer age and activity so you are not underfixing.

Best,

Doremus

Doremus Scudder said:

That and the danger of getting flakes of sulfur or silver on your film should be enough to warrant careful monitoring of fixer capacities, activity and shelf-life (especially with fixer stored for a longer time) in order to avoid underfixing in the first place.

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That's not contested. As for the preceding bit:

Doremus Scudder said:

Underfixed film often develops stains, which cannot be fixed out later. Underfixing can also result in the loss of image silver, as it degrades when exposed to contaminants.

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If you notice your film is underfixed, put it in fixer. Regardless of what can happen to it, do what is possible.