Weird sedimentation in FomaFix

[Boris Mirkov]

I have FomaFix with expiration date of february 2021, the bottle was opened some six months ago, when I wanted to use it I saw the sedimentation as seen it the photo, it collected on the walls and some more (and in thicker layer) on the bottom of the bottle and also floats around in the fixer. I am not going to use it, of course, but am interested in what went wrong. I kept it in the darkroom which is in my basement, temps this year ranged from 20ish to 30ish, never below or above it.

 

[Anon Ymous]

All acidic fixers eventually precipitate sulfur and this is likely what has happened. The bottle walls are covered progressively with sulfur crystals, some of which float in the liquid.

 

[blockend]

I put my fix through a tea strainer to remove crystals. Haven't had any short or long term fixative problems doing this.

 

[Boris Mirkov]

So it is usable, after all? My logic was, when I saw it - it is cheap and no point in saving very small amount of money and being prepared to mess up whole negative over it

 

[DeletedAcct1]

if it's colloidal sulfur no filter will do...

 

[Rudeofus]

if it's colloidal sulfur no filter will do...

Correct, don't use this fixer. Colloidal silver will eventually attack the image silver.

@Boris Mirkov : the fixer had expiration date a few months in future, but this expiration date only applies to unopened bottles. I you don't use fixer very often, think about getting neutral fixer, these have much better shelf life, both as concentrate and as working solutions.

 

[miha]

My 5L jug of Fomafix purchased last November, LOT 0708, exp. date 2021-30-09, half full right now, still looks OK.

It's strange that neutral fixers for fixing B&W material were never produced by a major mfg . Tetenal being the only exception with their Superfix geruchlos / odourless fix.

 

[relistan]

My 5L jug of Fomafix purchased last November, LOT 0708, exp. date 2021-30-09, half full right now, still looks OK.

It's strange that neutral fixers for fixing B&W material were never produced by a major mfg . Tetenal being the only exception with their Superfix geruchlos / odourless fix.

Agfa made Agfa FX Universal which was slightly alkaline. It's NLA for a long time now though.

 

[miha]

Interesting, thanks.

 

[Rudeofus]

It's strange that neutral fixers for fixing B&W material were never produced by a major mfg . Tetenal being the only exception with their Superfix geruchlos / odourless fix.

There are some offbrand products available in Europe, e.g. from Amaloco and Rollei. The magic word to search for is "odorless", not "neutral". You can also use any fixer recommended for color processes, sometimes there are very cheap specials on minilab fixer.

 

[miha]

Yes, I know they are available, what puzzles me is they were never available from Ilford, Kodak, etc, even it the hay day.

 

[DeletedAcct1]

Bear in mind that using neutral fixer is paramount to use also an acidic stop bath before.
No water rinses.

 

[Rudeofus]

Bear in mind that using neutral fixer is paramount to use also an acidic stop bath before.
No water rinses.

That may have been the reason. Bill Troop got massive flak for his alkaline fixers back then, I guess this did not exactly encourage larger manufacturers to explore this market. According to Bill Troop several automatic black&white processors secretly used alkaline fixers.

 

[relistan]

Bear in mind that using neutral fixer is paramount to use also an acidic stop bath before.
No water rinses.

Can you elaborate on why? This is the opposite of the recommendation of the Film Development Cookbook when speaking of alkaline fixer. They, Anchell and Troop, specifically say not to use acidic stop baths with alkaline fix. I can't see how a neutral fix is different. Logically, it would seem that an acidic stop bath would over time turn your neutral fixer acidic, where a neutral water bath would not.

 

[relistan]

That may have been the reason. Bill Troop got massive flak for his alkaline fixers back then, I guess this did not exactly encourage larger manufacturers to explore this market. According to Bill Troop several automatic black&white processors secretly used alkaline fixers.

You know more about fixers than me (I am about to try your posted recipe this weekend), but I had understood that long term shelf life was the main reason.

 

[MattKing]

As I understand it, most neutral fixers are reasonably well buffered. Photo Engineer posted many times on this site that TF-4 and TF-5 were both designed to work well with acidic stop baths.
I expect that Kodak never designed neutral fixers for black and white because C-41 fixer does that job perfectly.

 

[Rudeofus]

You know more about fixers than me (I am about to try your posted recipe this weekend), but I had understood that long term shelf life was the main reason.

The main reason were fast wash times. Long shelf life was no concern back then. Kodak eventually found, that neutral fixers have the same advantages re: wash time and shelf life, and they don't bring about this ammonia smell of alkaline rapid fixers. So neutral fixers it was. We must not forget, that Kodak's B&W research was not exactly hyperactive during the last 40 years, except for XTol there were no new Kodak B&W chemistry products introduced to the market.

Yes, Kodak's color fixers are extremely cheap and well suited for B&W work, but Kodak does not exactly go out of their way to mention this.

 

[john_s]

Agfa made Agfa FX Universal which was slightly alkaline. It's NLA for a long time now though.

In Australia, Agfa had quite a high presence, and the back label for FX-Universal (pH>7.0) showed dilutions for black and white.

 

[DeletedAcct1]

Let's put it clear: Tetenal odourless fixer is... odourless, not neutral nor alkaline!
On the contrary, the fixer https://www.fotoimpex.com/shop/images/products/media/6430_1_MSDS_DE.pdf is slightly acidic, having a pH of about 6,5.
That pH isn't sufficient to stop development if one uses a water wash after the developer. There's also a risk of dichroic fog.
Whilst a common fixer has much lower a pH that is sufficient to halt development even if a stop bath isn't used.

 

[DeletedAcct1]

In Australia, Agfa had quite a high presence, and the back label for FX-Universal (pH>7.0) showed dilutions for black and white.

I don't see a pH of 7 there

 

[relistan]

I don't see a pH of 7 there

Nobody said it was 7. He said ">7.0" which is "greater than 7.0" and I said "slightly alkaline". Agfa themselves called it "neutral". It was basically C-41 fixer with dilutions provided for B&W.

 

[DeletedAcct1]

Nobody said it was 7. He said ">7.0" which is "greater than 7.0" and I said "slightly alkaline". Agfa themselves called it "neutral". It was basically C-41 fixer with dilutions provided for B&W.

do you have an msds?

 

[relistan]

do you have an msds?

Nope, try Google. It's NLA for over a decade.

 

[mshchem]

When I open a bottle of fixer I divide it into nice 250mL Nalgene bottles, exclude all air. C-41, E-6, Kodak Rapid fix. Same with the Fixer part of RA-4 Bleach-Fix, keeps forever. A friend brought over a 5L bottle of Ilford Hypam, we developed a bunch of film. He didn't decant it I ended up throwing away half of it.

 

[Rudeofus]

Let's put it clear: Tetenal odourless fixer is... odourless, not neutral nor alkaline!
On the contrary, the fixer https://www.fotoimpex.com/shop/images/products/media/6430_1_MSDS_DE.pdf is slightly acidic, having a pH of about 6,5.
That pH isn't sufficient to stop development if one uses a water wash after the developer. There's also a risk of dichroic fog.
Whilst a common fixer has much lower a pH that is sufficient to halt development even if a stop bath isn't used.

A pH of 6.5 is ideal for color processing, and it also gives excellent shelf life both as concentrate and as working solutions. TF-5 also operates at this pH, with great success. At this pH a fixer is considered "neutral", unlike most commercial rapid fixers, which operate at pH 5 - 5.8.