Has my fixer gone bad?

Minolta93 · Aug 28, 2022

I have a bottle of KodaFix that seems have precipitated sulfur, or some other yellow material. If I shake it up, it doesn't seem to dissolve again. I tried diluting it to working concentration hoping it might clear up, but it's still cloudy and yellow. And it stinks. It's gone bad, right? Will it still fix film in it's current state?

If it has gone bad, are there fixers I can buy that won't go bad like this? I've only had the bottle for a few months.

MattKing · Aug 28, 2022

Kodafix is likely to precipitate quicker than standard Kodak Rapid Fix because with Kodafix the acidic hardener has been added, while with Kodak Rapid Fix you can elect not to add the hardener - which is usually a good idea anyways.
Unfortunately, it is harder to ship Kodak Rapid Fix, and you need to deal with the separate 3.5 oz bottle of hardener once you receive it - it is quite acidic. I use it when toning, but not everyone has a use for it.
Ilford Rapid Fixer or Hypam Fixer are both fixers that ship without hardener. There are other non-hardening fixers as well.

RalphLambrecht · Aug 28, 2022

Minolta93 said:
I have a bottle of KodaFix that seems have precipitated sulfur, or some other yellow material. If I shake it up, it doesn't seem to dissolve again. I tried diluting it to working concentration hoping it might clear up, but it's still cloudy and yellow. And it stinks. It's gone bad, right? Will it still fix film in it's current state?

If it has gone bad, are there fixers I can buy that won't go bad like this? I've only had the bottle for a few months.

Yes it has gone bad but, not all is lost. You can probably save it by filtering it through a regular coffee filter and use the filtered concentrate as usual. Nevertheless, it's time to order a new fixture!

Minolta93 · Aug 28, 2022

MattKing said:
Kodafix is likely to precipitate quicker than standard Kodak Rapid Fix because with Kodafix the acidic hardener has been added, while with Kodak Rapid Fix you can elect not to add the hardener - which is usually a good idea anyways.
Unfortunately, it is harder to ship Kodak Rapid Fix, and you need to deal with the separate 3.5 oz bottle of hardener once you receive it - it is quite acidic. I use it when toning, but not everyone has a use for it.
Ilford Rapid Fixer or Hypam Fixer are both fixers that ship without hardener. There are other non-hardening fixers as well.

And it's my understanding that hardening isn't necessary for modern films, is that correct? I may look at the Ilford options, unless there is something else you'd recommend.

RalphLambrecht said:
Yes it has gone bad but, not all is lost. You can probably save it by filtering it through a regular coffee filter and use the filtered concentrate as usual. Nevertheless, it's time to order a new fixture!

Would you suggest filtering the diluted bottle I've made or the concentrate itself for the best effect? I don't have any film to develop at the moment so I may just order a new bottle instead.

MattKing · Aug 28, 2022

Minolta93 said:
And it's my understanding that hardening isn't necessary for modern films, is that correct?

Mostly yes - particularly the major players like Kodak and Ilford/Kentmere and Fuji.
If by modern though you mean currently manufactured, there are some outliers (Shanghai?) that might benefit. And of course, people seem keen to try all sorts of unusual things with film, and try unusual things to develop film, and some of those experiments can lead to a need to re-harden emulsions. That is why I use the Kodak hardener when toning prints, because some toning procedures lead to softened emulsions.

Minolta93 · Aug 28, 2022

MattKing said:
Mostly yes - particularly the major players like Kodak and Ilford/Kentmere and Fuji.
If by modern though you mean currently manufactured, there are some outliers (Shanghai?) that might benefit. And of course, people seem keen to try all sorts of unusual things with film, and try unusual things to develop film, and some of those experiments can lead to a need to re-harden emulsions. That is why I use the Kodak hardener when toning prints, because some toning procedures lead to softened emulsions.

Thanks. For my purposes a non-hardening fixer should be just fine.

mshchem · Aug 28, 2022

Minolta93 said:
Thanks. For my purposes a non-hardening fixer should be just fine.

+1

cmacd123 · Aug 28, 2022

the sulfur is the fixing agent decomposing. (No longer thiosulfate) so it is basically not useful.

Brendan Quirk · Aug 28, 2022

cmacd123 said:
the sulfur is the fixing agent decomposing. (No longer thiosulfate) so it is basically not useful.

I tried some fixer with precipate once on some leader just to check - sure enough, it is useless. Had to toss gallons of old free fixer!

Minolta93 · Aug 28, 2022

So, just to clarify, a non-hardening fixer would last longer, right? If not, are there any specific fixers with a long shelf life?

MattKing · Aug 28, 2022

Right.
I've had good long life from Kodak Rapid Fix - in concentrate or diluted, without hardener added - and Ilford Hypam - also in concentrate, and diluted.

Minolta93 · Aug 28, 2022

Thanks again.

Rudeofus · Aug 29, 2022

RalphLambrecht said:
Yes it has gone bad but, not all is lost. You can probably save it by filtering it through a regular coffee filter and use the filtered concentrate as usual. Nevertheless, it's time to order a new fixture!

It will likely fix this way, but it will just as likely leave colloidal Sulfur in your film, which can cause damage down the road. PE strictly advised against doing this.

Minolta93 · Aug 29, 2022

Rudeofus said:
It will likely fix this way, but it will just as likely leave colloidal Sulfur in your film, which can cause damage down the road. PE strictly advised against doing this.

If PE advised against it then I just won't do it.

john_s · Aug 30, 2022

I read on this site recently that once the breakdown of acidic fixer starts, it accelerates because the pH declines, aggravating the reaction.

Minolta93 · Aug 30, 2022

john_s said:
I read on this site recently that once the breakdown of acidic fixer starts, it accelerates because the pH declines, aggravating the reaction.

I think I read that somewhere as well. Also something about there being additional chemicals added that buffer the degradation process and once they run out it breaks down.

I do find it curious that the diluted fixer solution did not go bad. Of course, it was sealed in glass bottle, but it did have a plastic lid. I can't be sure if it's the bottle or the fact that it was mixed with water that helped protect it.

RalphLambrecht · Aug 30, 2022

Minolta93 said:
And it's my understanding that hardening isn't necessary for modern films, is that correct? I may look at the Ilford options, unless there is something else you'd recommend.

Would you suggest filtering the diluted bottle I've made or the concentrate itself for the best effect? I don't have any film to develop at the moment so I may just order a new bottle instead.

I filtered the concentrate itself, threw out the coffee filter and it worked like new fier concentrate for me.

NB23 · Aug 31, 2022

RalphLambrecht said:
I filtered the concentrate itself, threw out the coffee filter and it worked like new fier concentrate for me.

Can you retrieve the fiber prints you fixed with that fixer?
How do they look?
How many years have gone by?

john_s · Sep 1, 2022

As far as alvage is concerned, I suppose it depends how far gone the fixer is. It could be stabilized perhaps with a little sodium hydroxide to prevent the acid from further destroying the remaining thiosulphate. I would use fresh fixer myself.

Rudeofus · Sep 2, 2022

RalphLambrecht said:
I filtered the concentrate itself, threw out the coffee filter and it worked like new fier concentrate for me.

Each molecule Sulfur you filtered out was replaced by Oxygen in a Thiosulfate ion, thereby creating Sulfate anion. This Sulfate ion has no fixing properties - to the contrary, it reduces swelling and thereby decreases fixing speed beyond the speed loss you already get from the lower Thiosulfate amount.

I know, experiments are more relevant than theoretical calculations, but I seriously doubt the "like new fixer" statement.

And this still ignores my statements about the colloidal Sulfur eventually destroying your silver image.

Rudeofus · Sep 2, 2022

Minolta93 said:
I think I read that somewhere as well. Also something about there being additional chemicals added that buffer the degradation process and once they run out it breaks down.

I do find it curious that the diluted fixer solution did not go bad. Of course, it was sealed in glass bottle, but it did have a plastic lid. I can't be sure if it's the bottle or the fact that it was mixed with water that helped protect it.

Fixer starts as a combination of thiosulfate and sulfite and some ingredients for buffering and sequestering. Initially the sulfite takes all the Oxygen, forming sulfate until it is all gone. pH will slowly decrease in this process. Once all the sulfite is oxidized, Oxygen will go after the thiosulfate, converting it to sulfate, further lowering pH of this solution. Below a certain threshold pH thiosulfate will disintegrate into sulfite (which again reacts with Oxygen) and Sulfur (this is the yellow precipitate). Buffering can slow down the process by keeping pH above the level where thiosulfate breaks apart.

Has my fixer gone bad?

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