ThomasPauly
[size=4][color=#000000][font=Calibri]Do the various fixer solutions actually differ in terms of how easily they rinse out? For example, can I apply the convenient and water-saving Ilford method for film washing (which the manufacturer naturally only recommends for its own Hypam product) to the Calbe A 300 powder fixer, for instance, without risking any compromise to archival stability?[/colo
[color=#000000][font=Calibri]Background to my question: For liquid fixer concentrates, the product data sheets state that the shelf life in opened bottles is only a few months. Even though the manufacturers are probably erring on the side of caution here, I am considering whether it might be better to use the powder-based chemicals – which have a long shelf life and are available in 1-litre containers – during periods of low throughput. However, I think I once read that (certain?) liquid formulations wash out more quickly than powder fixers. Is that actually true?[/colo[/size]
[size=4][color=#000000][font=Calibri]Regards[/colo
[color=#000000][font=Calibri]tepe[/colo[/size]
piu58
The rate at which the dye leaches out differs between acidic and neutral fixers; the neutral fixer leaches out more easily. Otherwise, the differences are minor.
SxDx
When developing film, you can apply the Ilford method (or any other method) to all fixers. After all, the film is fully washed through in just a few minutes anyway. The differences are particularly significant with baryta paper, because it’s a real bonus when you only have to wash for half an hour instead of a full hour.
michael-kielgmxnet
A modern liquid fixer will certainly last longer than a few months, provided, of course, that it is stored correctly. With the brands I use (Rollei RXN for paper and C41, and Agfa Agefix for the residue), I have never had any problems with shelf life.
The Calbe A300 is a relic from a time when rapid fixers were still unknown. The fixing times are much longer than with a modern fixer, and the capacity of the working solution is likely to be lower too.
piu58
> It will certainly last longer than a few months if stored properly
I’ve had problems with fixers before, specifically sulphur deposits (yellowish flakes). If you use this one, you end up with brown sludge, so it’s not recommended. Such deposits are typical of fixers and are certainly found in fixer bottles that have been in use for a long time.
Storage in cold conditions is particularly critical. A300 is much more stable and can be stored for decades even in very cold conditions. However, the fixing time is about twice as long, so you need to consider whether you want to go to that trouble.
hypeo
However, the fixing time is about twice as long, so you have to think carefully about whether it’s worth the hassle.
With film, I don’t really mind, as I only develop a maximum of two rolls a month anyway. With paper, however, if you also take test strips into account, you could save a lot of time simply because of the shorter fixing time.
A modern liquid fixer will certainly last longer than a few months, provided it is stored properly, of course.
For me, the Adofix working solution (1+7) lasts at least a month in the bottle. I haven’t tested it for longer, as I only fix two films in the working solution anyway, and it’s therefore used up after a month at the latest.
It’s stored in a Jobo wide-neck bottle, as fixer doesn’t (or hardly?) oxidise.
piu58
> For me, the Adofix working solution (1+7) lasts at least a month in the bottle
The working solution is not a problem. The concentrate breaks down much more quickly.
ThomasPauly
How can I reliably tell when a concentrate or working solution has become unusable over time?
I know that there are fixing bath test strips for the working solution.
But what about the concentrate?
SxDx
As long as the concentrate shows no signs of sulphur precipitation, it is still good. It does not gradually deteriorate like a developer, because the relevant substances are relatively stable.
hypeo
As long as the concentrate hasn't started to show any sulphur deposits, it's still fine.
How can you tell if this is the case? As you know, the Adofix bottle is black, and when the bottle is left to stand undisturbed, these precipitates will certainly settle ‘invisibly’ at the bottom.
SxDx
If you really have any doubts, I’d transfer the concentrate to another bottle and cut open the old plastic one. You can usually tell just by pouring it out, though.
But as long as the stuff isn’t several years old, I wouldn’t worry about it. I haven’t had a fixer go off in the 1–2 years it takes me to use up the concentrate. And I always leave it in the plastic bottle it comes in. So no protective gas and no decanting into smaller storage bottles.
piu58
You’ll notice this when you prepare it; there are these yellowish flakes floating in it. As you use it up bit by bit, the fixer doesn’t just go off all at once, but gets progressively worse. You might just about be able to put up with the first few faint flakes. What you notice when using it is that the fixer changes colour, becoming a brownish-yellowish opaque (colloidal) mass due to silver sulphite. It still fixes, but I don’t use it once it’s got to that stage. If the decomposition is more severe, a proper sediment (black) forms during use. This is, of course, a real hazard, even if the stuff still fixes: it can scratch films and paper surfaces as well.
piu58
- Double post -
Morte
If the product has deteriorated significantly, a distinct black residue forms when used. This is obviously a real hazard, even though the stuff still works: it can scratch film and paper surfaces too.
Aha! That finally explains the silvery-black film in my plastic bottle containing the diluted developer (Adofix). It still works well, but I couldn’t explain it before.
Is it enough to clean the bottles with a bottle brush before making a fresh batch with new chemicals, or will small residues contaminate the new batch?
piu58
> Will small residues contaminate the fresh batch?
No, silver sulphite is stable and does not undergo any chemical changes in fresh fixer. There simply must be no loose particles floating in the tray or container.
hypeo
There simply mustn’t be any loose particles floating around in the tray or tin.
In other words, if you filter out these loose particles – provided they are coarse enough – is there nothing that will ‘break down’ the fixer over time or damage the film?
piu58
> Is there anything that ‘breaks down’ the fixer over time or damages the film?
I can’t see any chemically harmful effects. Of course, if the fixer is completely or almost completely decomposed, it will no longer work.
Thiosulphate is produced by boiling sulphite with sulphur.
This process is reversible and proceeds particularly well in the cold (which is obvious), and is promoted by the addition of acids.
This then produces sulphite and sulphur again. Silver sulphite is almost insoluble, though not to the same extent as silver sulphide, and precipitates out.
dudestyle
I’ve had those cloudy streaks in the fixer—the working solution—before, after it’s been left standing for a while. I reckon that’s just some sort of sediment.
