Lasts only 1 day in a capped bottle -Ilford Cooltone Paper Developer Working sol'n

[PeterB]

The bottom of the last page of the Ilford Cooltone data sheet reads "If stored in a tightly capped bottle (it) may last up to 24 hours."

Then what happens ??
I've had a tightly capped bottle of a 1+9 working solution made up for 7 weeks now, I've had it out about 4 times in a tray for a couple of hours each time and developed a total of only 6 prints with it. The prits are consistent and seem to be OK.
Why are Ilford sooooo conservative with their expiry date, or
Is my dev actually off and I don't realise it ?!

rgds
Peter

 

[Eric Rose]

I've been using mine for several months now and it seems fine.

 

[Ian Grant]

Peter, the recommendations are generalities, not everyone will store it as well as others. Yes it might last longer but you may not be noticing a slight dropping off in quality unless you tried weeks old solution against fresh.

My experience has always been that older developer is just not as good as fresh, regardless of the formula, and I always use fresh developer every session regardless of how few prints I might have made,

Ian

 

[Martin Aislabie]

If I want to store my Print Dev overnight, I pre-fill the bottle with inert gas

I use Tetenal Protectan but any similar photographically inert gas will do - http://www.tetenal.com/openerimg.htm?file=imaging_shop/images/105193.jpg

My thinking is, when the Dev gets poured into the storage bottle, there is a lot of churning and splashing which could increase oxidation.

By eliminating the oxygen you eliminate the oxidation.

Unlike Ian, I will re-use Dev but only if I am proofing or contact printing Negs for filing, never for anything serious.

Martin

 

[PeterB]

Yes it might last longer but you may not be noticing a slight dropping off in quality.
Ian

Hi Ian,
can you be more specific about what I should be looking for when the 'quality' deteriorates ?
I need to know what to look for !
regards
Peter

 

[Anon Ymous]

Hi Ian,
can you be more specific about what I should be looking for when the 'quality' deteriorates ?
I need to know what to look for !
regards
Peter

Well, I'm not Ian, but I have some experience about using Ilford's Multigrade developer after it's supposed useful life, which has (according to them) the same keeping properties with cooltone. It's not that it will die within a day if you bottle it. Actually, it will take some days to be able to distinguish differences between old and freshly mixed developer. When you'll be able to spot the differences, it will be slightly less contrast and slightly warmer image tone (with multigrade developer). Both solutions gave nice blacks. I had to make side by side tests with the same paper, negative, exposure (...) developed in fresh and (IIRC) 2 weeks old developer. The old solution wasn't used heavily and hadn't reached half of the stated capacity.

I'd expect the same things to happen when using cooltone too, but keep in mind that the way you store the solution and other variables will certainly affect it's behavior. Anyway, if you're picky, use fresh solutions for every printing session. If not, store and reuse.

 

[monodave]

Dilute developer contains little developing agent and what little is there will be rapidly oxidised by air. If you value your print quality you should use fresh developer for each day of printing or when the blacks and contrast seem degraded. Fresh dilute developer will be good for 30-odd 10 x 8 inch prints or equivalent at most. Dave

 

[PeterB]

Many thanks Anon ! You have told me what to look out for. i.e. slightly less contrast and a slightly warmer image tone.

And Dave thanks for the tips. I use fresh mixed dev for final prints, however I need to know for my test prints what to look for to know when the dev is on the way out. I only have time at the moment to develop 1-2 test prints each time I pop into the darkroom (in what little spare time I have), so I can't see any point mixing fresh dev every session unless I have to.

rgds
Peter

 

[dancqu]

But Lots of Sulfite --- Consistency Not Quality

Dilute developer contains little developing agent and what little
is there will be rapidly oxidised by air. If you value your print
quality you should use fresh developer for each day of
printing or when ... Dave

Sodium sulfite in quantity preserves the developer. It also
oxidizes. Among the few factors which affect a developer's
keeping characteristics is catalytic accelerated oxidation of
the sodium sulfite. For example a minute trace of copper
in water will cause an increased rate of oxidation.
Minute amounts of other impurities will likely
also contribute to the sulfites demise.

Consistency is the issue not Quality. Quality has to do with
finger prints, stains, uneven development, fog, .... ?
Likely you've in mind another factor or two which
affect quality. Dan

 

[pentaxuser]

PeterB. You might see the effect looking at one print in isloation but it may require that you keep a print developed in fresh dev for comparison. It certainly has "crept up " on me without being aware of it and the sign that eventually alerted me to a problem was the need to change grades on a print. Most were OK at grade 2 then one neg needed grade 3.5. The result was no difference in the print! The dev was still working after a fashion but has "died" in terms of doing what it should

pentaxuser