When are chemicals ready for the retirement home?

[Korona]

Yesterday I cleaned out the old darkroom that my dad and I used to use at his house, in preparation for putting my new darkroom into service. (Will primarily be used to make 12x20 contact prints.) Most of the ‘consumables’ are approx. 10 years old. Common sense says some of the chemicals are clearly no good anymore (developers, etc.) and others will clearly still be good (stop bath, photo-flo, etc.).

But there are some ‘in-between’ items I’m not sure about, and as some of these tend to be a little costlier I hate to just toss them. (Plus why create extra waste if not necessary?) Examples:

Ilford Rapid Fix (5 liter, to make up to 50 liters). Full or nearly so. $20?.
One gallon of Kodak fixer (working strength).
Kodak Rapid Selenium Toner (1 qt.). Unopened, still clear. $20?
Kodak Hypo Clearing Agent (unopened envelope, to make 5 gal). $7?

Lots of paper also, but I can easily test that and see what condition it’s in. The problem with the above chemistry is that it’s harder to test (esp things like fixers and clearing agents, etc) without waiting a few years and seeing if the prints fade(!) My gut instinct is that fixers aren’t complex organic chemicals and thus might have a long shelf-life, but I don’t really know.

I know the obvious ‘safe’ choice is to toss everything and start over (and I’m happy to do that, if required) but before I put a bunch of potentially good chemicals down the drain I thought I’d look for further data.

So… any direct experience here, or objective, scientific input? (Not all that interested in random guesses.)

Thanks much! Really looking forward to having my own working darkroom again!

Mark

[Doremus Scudder]

Powdered developers stored in air-tight packaging may be good for years. Liquid developer concentrates such as Rodinal and HC-110 also last years. Mix some and make a quick test. If they mix clear, and darken a film strip quickly in the same time as fresh developer, then they are just fine.

Of the things you list, the selenium toner is most probably still good, as is the unopened Hypo Clear. The toner will be good unless contaminated; the Hypo Clear is okay if it is in its original air-tight packaging. I would go ahead and use these.

The Ilford Rapid Fix concentrate has an approximate 2-year shelf life. If there is yellow sulfur precipitate on the bottom, it is no good; I wouldn't risk it in any case; fixing is a critical step. The working solution of fixer is certainly no good. Toss both of them.

Hope this helps,

Doremus

[Arne Croell]

As Doremus said, the fixer is a problem. Liquid acidic fixer concentrates tend to produce sulphur precipitates after a while (this probably does not apply to neutral/alkaline fixers, but they are not as common). If it has not yet happened, it is possible to delay that reaction by adding some sodium sulfite (because Na2SO3 + S -> Na2S2O3, aka sodium thiosulphate aka "hypo"). It actually also works if you already have visible sulphur crystals, but takes forever (like a year or more). I tried it once out of curiosity, but its not worth the effort; you also have to do it in a glass bottle because otherwise oxygen from the air will produce mostly sodium sulfate out of the sulfite (Na2SO3 + 1/2 O2 -> Na2SO4).

[Korona]

Thanks a ton for the info, guys! The toner and the hypo-clear stays, the fixer goes - got it. Also thanks for the chemistry lesson... interesting how you can turn the sulphur precip back into sodium theosulphate. Don't have a year to do that, but still very interesting from a scientific viewpoint.

Cheers!
Mark