C41 fixer turned yellow and started to stink

VPooler · Feb 17, 2014

Hello!

I just did two rolls of ECN2 film in C41 chemistry with developer switch (mixed the real developer and it was a success!) but after the first roll the fixer bath turned slightly yellow and started reeking of rotten eggs and other foul things (it stinked already when mixed but not that badly!). It was plain nasty. I did a proper wash after bleach. The fixer worked OK for other roll, though. Is this normal? The fixer and bleach were Calbe RA minilab ones.

Mr Bill · Feb 17, 2014

VPooler said:
...the fixer bath turned slightly yellow and started reeking of rotten eggs and other foul things (it stinked already when mixed but not that badly!). It was plain nasty. I did a proper wash after bleach. The fixer worked OK for other roll, though. Is this normal?

No, not normal. It sounds like it is decomposing, and free sulfur is the result. So don't use the fixer.

In normal fixer, there is a reaction with sulfite ion that somehow reconverts thus sulfur back into thiosulfate. My guess is that your sulfite is all gone, possibly from long time exposure to air. If you happen to have some sodium sulfite around, you might try adding some, say 5-10 grams per liter, to see if this clears it up. But again, don't use it as is.

VPooler · Feb 17, 2014

Mr Bill said:
No, not normal. It sounds like it is decomposing, and free sulfur is the result. So don't use the fixer.

In normal fixer, there is a reaction with sulfite ion that somehow reconverts thus sulfur back into thiosulfate. My guess is that your sulfite is all gone, possibly from long time exposure to air. If you happen to have some sodium sulfite around, you might try adding some, say 5-10 grams per liter, to see if this clears it up. But again, don't use it as is.

Dumped 15g of sodium sulfite in and stirred through. It has been 10 minutes and fixer is still yellow and reeks. Works ok though. The concentrate came from a half-used canister, what was that way for quite a while. Yet my B&W half-used concentrates have worked perfectly.

EDIT: it works INCREDIBLY fast. Cleared the test strip in mere 10 seconds at room temperature.

EDIT2: Smells like ammonia, instead of rotten eggs. No precipitate. Could be too alkaline as pH meter reads 7.03 @ 25 degrees centigrade.

Gerald C Koch · Feb 17, 2014

Once a fixer starts to sulfurize it really can't be saved. If it is just beginning to turn milky the addition of sulfite may help. Sounds like your's is beyond the pale. Dump it.

VPooler · Feb 17, 2014

It is completely clear, just has a yellow tint. I know what you mean by milky, I have a bottle of rapid fixer from the 90's here that is milky with a yellow precipitate.

VPooler · Mar 26, 2014

UPDATE: The fixer still is yellow and smells like piss but it works perfectly.

Photo Engineer · Mar 26, 2014

I would not use it. It is probably forming Hydrogen Sulfide gas which smells like rotten eggs, along with Sulfur. Don't trust it.

PE

Rudeofus · Mar 27, 2014

Fixer used for C41 and E6 should have pH 6.5. If the pH of yours is too high, it will smell of Ammonia. You can use Acetic Acid to bring it down.

VPooler · Mar 27, 2014

I diluted it before with water and the smell went down. I will drip some vinegar in it when I get back home. Seems that I forgot to dilute it in the first place

Rudeofus · Mar 27, 2014

VPooler said:
I diluted it before with water and the smell went down. I will drip some vinegar in it when I get back home. Seems that I forgot to dilute it in the first place

Of course dilution will bring down the Ammonia smell, because vapor pressure is lower. You should check clearing time with that diluted fixer, just in case you diluted it twice by accident. Too high dilution would mean long clearing time and much lower capacity.

Photo Engineer · Mar 27, 2014

The OP says "rotten eggs" and not "ammonia", and thus the solution has gone totally bad and cannot be fixed.

PE

Rudeofus · Mar 27, 2014

Photo Engineer said:
The OP says "rotten eggs" and not "ammonia", and thus the solution has gone totally bad and cannot be fixed.

He corrected himself in later postings in this thread.

VPooler · Mar 27, 2014

Rudeofus said:
He corrected himself in later postings in this thread.

Yes, it smells like regular ammonia.

Clearing time is still very fast, strip of Kodak 500T clears in some 20-30 seconds completely. pH still reads neutral.
It is not about salvaging the solution, I have enough concentrate to mix up another 3-4 liters, I just don't want to pour out usable chemicals.

Photo Engineer · Mar 27, 2014

Well, since this change in odor took place after adding Sulfite, I connected the two (and the noted pH value) and assumed that had changed the pH upwards and the original post was correct.

It is hard to diagnose this from a distance.

Rotten Eggs denotes a total decomposition at an acid pH, and the yellow color supported this. Ammonia odor says alkaline pH and you usually do not get a yellow color. So, I am at a loss. The correct pH for C41 fixer is about 6.5 and it should be odorless. It should be clear and colorless as well.

PE

VPooler · Mar 28, 2014

Well, I take it as partially ruined, partially working. Will do clearing tests prior to further use and I will not replenish it as planned, instead I am going to exhaust it and store separately from other spent fixer (going to silver recovery). I guess something was off with my processing that partially murdered the solution. Thankfully, the bleach is still alive, as it is the hardest to replace for me. Developer was not kept, as ECN2 (yup, did ECN2 with C41 back-end) does not keep well anyway. Thanks for the replies!

C41 fixer turned yellow and started to stink

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