FIXER D-I-Y TEST

[joho]

I have made a fixer for film & paper a test but
first -- this is the recipe

1 lt. water with
ammonium hypo 300gr.
sodium hypo 200gr.
S. metebisulpite 40gr.
S. sulphate 40gr.
P. alum 05gr.

what would be the correct working solution ?????? 1 to 3???

 

[Rudeofus]

What's the supposed point of this formula? It's an acidic hardening fixer (barely useful today), which mixes Sodium Thiosulfate with Ammonium Thiosulfate - you combine the high cost of Ammonium Thiosulfate with the poor capacity of Sodium Thiosulfate. It may be inspired by some older Fuji patents which suggested that combination but ultimately went nowhere.

If you insist in using this fixer, then I'd go for 1:2.5 for fixing films and 1:5 for fixing paper. Expect long fixing and washing times.

 

[koraks]

I agree with @Rudeofus; this formula is essentially a waste of perfectly good ammonium thiosulfate.

 

[joho]

It was an experiment - which as has long times !!-and it does not clear the film base ?????????

ok you all don't have to hit me the same time

 

[koraks]

ok you all don't have to hit me the same time

No worries, we can take turns, LOL!
It's all good in the spirit of experimentation, right!

 

[joho]

all good!
do have a question -I used S. sulphate vers. S. sulphite would that make a big difference ???

 

[Don_ih]

I used S. sulphate vers. S. sulphite would that make a big difference ?

I think the likelihood is sodium sulphate did nothing in your formula.

 

[Mr Bill]

all good!
do have a question -I used S. sulphate vers. S. sulphite would that make a big difference ???

Well, maybe, I'm not sure. I'm guessing that you have realized that the sulfAte was the wrong thing (it should probably have been sulfIte (with an i).

I would expect that the pH of your fixer has gotten too low as a consequence of not using sodium sulfite. But I would guess it would still fix film. What sorta happens is that the sodium sulfite will tend to slightly raise the pH of the fixer. Whereas the sodium metabisulfite will tend to lower pH. The ratio between those two - sulfite vs metabisulfite - sets the working pH. So without sodium sulfite I expect the pH to go low.

If you're just experimenting you might just try adding the missing sodium sulfite. This oughta get the pH up near the normal aim. I would expect that the sodium sulfAte is mostly benign (concur with Don_ih).

If you leave the fixer as is, I would not be surprised if it "collapses" ("sulfurs out") in a somewhat short period of time. This is mainly a consequence of the pH being excessively low. Rudeofus is probably more up on this than I, but I think a pH of somewhere around 4.0 or lower is the breaking point where it wants to self destruct.

 

[Rudeofus]

I think the likelihood is sodium sulphate did nothing in your formula.

Looking at the combo of Sodium Sulfate plus Potassium Alum plus anything acidic like Sodium Metabisulfite: the idea was likely to provide some hardening function to the fixer. Both the sulfate and the alum will do this, and the metabisulfite maintains a low enough pH to prevent Aluminum Hydroxide precipitation. If you add Sodium Sulfite to this mix, you will get just this, so please don't.

Regarding one of the original questions: why doesn't this fixer clear film? This fixer is too concentrated as it is, you have to dilute it and it will fix film. Fixing action starts at rather low thiosulfate levels (think: 100 g/l) and then becomes faster and faster until you reach somewhere between 250 and 300 g/l, when fixing speed suddenly drops. Sodium Thiosulfate and Ammonium Thiosulfate will behave very similarly in this regard. Fixer concentrate will typically not clear film at all.

 

[Don_ih]

Fixer is not like developer. There's no great reason to mix your own. Some people like plain Sodium Thiosuphate fixer. But other than that, premixed rapid fixer is the most economical and convenient.

 

[Doremus Scudder]

Fixer is not like developer. There's no great reason to mix your own. Some people like plain Sodium Thiosuphate fixer. But other than that, premixed rapid fixer is the most economical and convenient.

+1

 

[joho]

I am reading and thinking !!

 

[relistan]

Fixer is not like developer. There's no great reason to mix your own. Some people like plain Sodium Thiosuphate fixer. But other than that, premixed rapid fixer is the most economical and convenient.

I keep some of the ingredients around and mix up @Rudeofus' nice fixer (see resources section) when I run low on commercial stuff and don't have time or can't go to the store. It's also nicer for a printing session since you don't have to breath the fumes. There are arguments to be made (and oh, have they) about longevity of prints and films due to the pH of the fixer. But you are right that you are not going to get any different performance in terms of photographic output.