Dead Fixer?

[Logan Becker]

Just mixed up a gallon of Kodak fixer and it's been slightly yellowish-green and milky for about a half hour. Package was intact and wasn't bloated, I'm a tad reluctant to test it.

I know fix has a short shelf life once it's been liquid-ized- haven't dug up anything on what it is for the dry stuff.

 

[jimjm]

I've mixed up powdered Kodak fixer that was about a year past it's expiration and it was fine. The working solution I have safely used for up to 2 months in a full bottle if it hasn't been exhausted. I do extend my fixing times as I fix more rolls and/or the solution ages.

If your fixer hasn't cleared after mixing, is it possible there was some other contaminant or residue in your mixing container? Maybe your tap water has some mineral or chemical that's reacting with the powder.

I'd do a test on an exposed piece of film leader. See how long the film takes to clear and double that to get your fixing time. If it takes more than 5 mins to clear in fresh fixer, then I'd suspect that the powder may have been compromised in some way.

 

[zanxion72]

Stock solutions of fix has long shelf life. Working solutions have a fair one too and can be re-used until they no longer work as expected. Get a piece of film and see after fixing if the cleared area has any defects (fog, spots, etc). If it comes out perfectly clear, then the fixer is usable.

 

[MattKing]

Be wary of using milky fixer. If there are particles suspended in it, they will most likely damage your film.
If it is clear, a clip test will tell you what you need to know.

 

[Gerald C Koch]

When mixing acid fixer it is important not to exceed the recommended water temperature. Higher temperature can cause the thiosulfate to sulfurize to form a milky solution of sulfur particles. As Matt says these particles can stick to the film emulsion and cause damage.

 

[Logan Becker]

When mixing acid fixer it is important not to exceed the recommended water temperature. Higher temperature can cause the thiosulfate to sulfurize to form a milky solution of sulfur particles. As Matt says these particles can stick to the film emulsion and cause damage.

I think that may have been the case. Will it eventually clear?

 

[Ryuji]

Is it a hardening fixer with dry powder thiosulfate and alum? I would suspect decomposition of thiosulfate and possibly reacted with the alum. If the insoluble is not very much, I would take the clear supernatant, add some metabisulfite (the fact that thiosulfate decomposed suggests a possibility of sulfite being oxidized, so some fresh metabisulfite needs to be added for stability), and use it. but otherwise throw it away. You don't want the solid particles in the processing solution (potentially difficult to wash if adsorbed on film surface).

 

[Gerald C Koch]

No once sulfurization begins it cannot be cleared. I the OP case the sulfur particles are quite fine making it difficult to filter.

 

[MattKing]

Is it a hardening fixer with dry powder thiosulfate and alum? I would suspect decomposition of thiosulfate and possibly reacted with the alum. If the insoluble is not very much, I would take the clear supernatant, add some metabisulfite (the fact that thiosulfate decomposed suggests a possibility of sulfite being oxidized, so some fresh metabisulfite needs to be added for stability), and use it. but otherwise throw it away. You don't want the solid particles in the processing solution (potentially difficult to wash if adsorbed on film surface).

Good to see you posting again, Ryuji.