Black sooty deposit in film fixer

[FilmShooterX]

I recently started using Diafine film developer (Bellini Duo-Step). I like using it but I noticed dark sooty deposit in the fixer (Ilford Rapid fixer). It gets quite bad and I have to use coffee filter to get rid of the deposit. In the past I used Rodinal and never experienced this before. Is this normal? I have attached a few photos here. You can see the deposit on the inside of the bottle and the deposit after filtering.

 

[Ian Grant]

That's typical for fixer, it's colloidal silver.

Ian

 

[grain elevator]

Typical yes, but is he fixer still good? How old is it, how many rolls have gone through it, do you use stop bath or a water rinse, how long is the clearing time, does it smell sulfur-y?

 

[FilmShooterX]

Thank you all. Only two rolls of films through the fixer. Fixer is still good. There is no stop bath stage using Diafine. It is interesting when I was using Rodinal, I did not see these deposit. I will just filter the fixer each time before I use it.

 

[Daniela]

I find that amount of silver surprising after only two rolls. It usually takes mine a lot more developing to see those deposits.

OP, one way to double check if the fixer is still good is to use a piece of the film you're about to develop, put it in the fixer and see how long it takes to clear. Then, you double that time and add one minute for your roll.

Edit to ask: what do you use for filtering the fixer?

 

[Don_ih]

There is no reason to not use stop bath. At the very least, after the second bath of the Belini stuff, rinse the film with water. When you put active developer in fixer, it causes the silver in the fixer to precipitate out - expect it to get on the film, as well - and it wears out your fixer.

 

[FilmShooterX]

The instruction for Belini Duo Step.

1) Develop your films in Part A for a minimum of three minutes using GENTLE agitation for the first 20 seconds then five seconds each minute at the one minute mark and for five seconds prior to draining. Old school Diafine users advise that too much agitation will result in a reduction of shadow detail. 2) Drain, DO NOT RINSE and especially do not use an acidic stop bath 3) Add Part B and again, develop your films for at least three minutes using the same agitation as per Part A 4) Rinse in water for 20 to 30 seconds then fix, wash and dry as normal. Job done!

There is no stop bath step.

I find i have to filter out the deposit after each use of the fixer. I will mix new fixer and try again.

 

[Don_ih]

There is no stop bath step.

This is the stop bath step:

4) Rinse in water for 20 to 30 seconds

That should be, if you're using a tank, fill and empty the tank with clean water several times, then pour in the fix.

Active developer getting in is ruining your fixer.

 

[koraks]

Active developer getting in is ruining your fixer.

There is indeed also a risk of dichroic fog if no stop bath or rinse is used between the second developer step and the fixer.

I find that amount of silver surprising after only two rolls. It usually takes mine a lot more developing to see those deposits.

How much is actually deposited depends on various factors. In a quantitative sense, the amount of silver I see in the photo of OP's fixer bottle isn't very large for two rolls of film. If a stop bath is used and the fixer isn't kept around for a very long time, the amount of deposited silver will generally be much less or even absent.

 

[khh]

I've had the same happen after two rolls of film, even though I do use stop bath. I was actually using Rodinal as the developer, that time. It just happens sometimes. I still haven't figured out how to get that bottle clean again.

 

[koraks]

I still haven't figured out how to get that bottle clean again.

You could use any kind of (strong) silver solvent; there are many, but common in home darkrooms are things like potassium ferricyanide. Add a teaspoon to some (fresh) fixer and slosh that around in the bottle until all the silver is gone. Alternatives are strong oxidizers like potassium permanganate or dichromate (kind of nasty, that one).

Mechanical removal sometimes works reasonably well, too, at least on glass bottles/jars. Cut a piece off of a metal scouring pad, and put this in the bottle/jar with half a cup of and with a bit of soap. Put on the cap and keep shaking the bottle/jar vehemently until the silver is all removed from the inner walls of the vessel.

Mechanical removal is the more benign approach, chemically speaking. I'd do that first, and then remove the silver remnants by chemical means.

An overall quicker way is to discard the bottle and use a new one, or appreciate the sight of a silver-plated bottle (best not to be used anymore for other purposes)!