White dust after c41

[yya]

So you're getting these white spots after fixing & washing, and you've used both Ilfocolor fix (as in your very first post) as well as Kodak fixer?
Is it possible that the wash is the problem? How are you washing the film exactly? And how about my earlier suggestions about avoiding dust in the drying environment? Has that yielded anything? At least you've now narrowed it down to the final stages of the process.

Yesterday I developed two rolls of 135 film. One was processed with Ilfocolor and rinsed with distilled water before drying. The other was developed with Kodak chemistry. After finishing the bleach step, I did two rounds of water wash and checked the negatives — they were clean without any spots. However, after the fixer step, spots started to appear. I then rinsed the negatives multiple times with warm water, but it didn’t help. This morning, I found that the spots could be rubbed off by hand, which suggests they were some kind of deposit.





From what I’ve researched online, fixer can crystallize at lower temperatures. It’s been pretty cold in Sydney lately, around 5°C at night. I mixed my fixer at room temperature, about 17°C, and while stirring I noticed a lot of tiny bubbles. In contrast, the developer became completely clear once the bubbles settled after stirring. This makes me suspect that the spots might be caused by fixer crystallization leading to deposits on the negatives after fixing.

 

[koraks]

The components in fixer are very readily soluble. While the fixer itself can crystallize at low temperatures, as soon as you bring it back up to room temperature, everything will go back into solution again.

Do you dilute the fixer with tap water or demineralized? If using tap water, I can imagine how crystallization of the calcium salts in the tap water at low temperatures may play a role, perhaps with some nucleation process taking place that results in unusually big agglomerates. IDK.

There's still the suggestion of the acid wash. Did you follow up on that?

 

[yya]

The components in fixer are very readily soluble. While the fixer itself can crystallize at low temperatures, as soon as you bring it back up to room temperature, everything will go back into solution again.

Do you dilute the fixer with tap water or demineralized? If using tap water, I can imagine how crystallization of the calcium salts in the tap water at low temperatures may play a role, perhaps with some nucleation process taking place that results in unusually big agglomerates.

The water is ultra pure water, but still slightly inferior to distilled water. Today, I will continue experimenting with real distilled water.

 

[koraks]

There's still the suggestion of the acid wash. Did you follow up on that?

 

[yya]

yes

 

[koraks]

...and....

 

[yya]

...and....

acid nothing help

 

[koraks]

What did you do exactly?

 

[yya]

What did you do exactly?

I want to do an experiment: soak a film leader directly in fixer and take it out to see if there are any spots, because it’s clear that the issue occurs after the bleach step.

 

[koraks]

Good idea! Although if you dry film with fixer still on it, you will definitely get crystallization of fixer components. So you'll need to rinse the film for the experiment to be meaningful.

 

[yya]

Good idea! Although if you dry film with fixer still on it, you will definitely get crystallization of fixer components. So you'll need to rinse the film for the experiment to be meaningful.

yes I will

 

[BMbikerider]

Does or did this happen with one film or more than one? I am playing 'catch up' because of other tasks I have not been around for as often as I can be. The only time I have ever had a residue deposit itself on a colour film was when I overstepped the mark with the bleach stage where the bleach was so exhausted I almost called an undertaker! If I am reading you right, correct me if I'm not but the developer is only used once - like me, but the bleach and fix are used a number of times. If it is the latter, how many films do you process with the same bleach and fix?