Storage time for selenium, sepia toner, fixer and stop bath

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I have just set up my own darkroom, and was wondering if more experienced printers could give me some information on chemical storage. (Before, I used a community facility and never had to worry about this, but had little flexibility in chemical choices.)

How long can fixer, stop bath, mixed selenium, and mixed sepia toner and bleach be stored in brown bottles before it needs to be discarded? I have test drops for checking fixer, but what are the early signs to tell that stop bath and selenium are exhausted?

Thanks in advance for the advice/assistance. Writing from Washington, DC where we are trying to get back to normal. Many of us know at least several of the people that were either killed in the plane or are still missing at the Pentagon. Nothing like New York, but still troubling. Odd this morning seeing a Red Cross blood transport vehicle being escourted by four police cars and two police motor cycles.

-- Jim Rock (jameswrock@aol.com), September 12, 2001

Answers

Greetings,

I'll try and answer as best I can.

Fixer can be kept for quite some time as a stock solution and it doesn't require a brown bottle. Once mixed to working strength, it can still be reused, but keep in mind the the capacity of the working solution. I would strongly recommend against approaching those capacities if you want archival results.

Stop bath is simply an acidic solution (vinegar would work) and doesn't require brown bottles for storage. The solution will last until all the water evaporates, or the acid is neutralized.

Selenium can be reused until it stops working. You can judge this by the change in tone on your prints. If you have to extend the time in selenium to achieve the same tone, then you need to replenish your selenium with fresh. There is no need to discard used selenium. It will discolor and solids may form in the solution, but it's no reason to discard it. Simply run it through a coffee filter and reuse it. As the volume of solution decreases, replenish it with fresh selenium mixed to the required dilution. Again, brown bottles are not needed.

Sepia toner and bleach also do not require brown bottles and will keep until the become exhausted.

If you're really concerned with the archival quality of your FB prints, then don't use the test solution. Use fresh fixer and change it frequently, preferably using the two bath method.

Regards,

-- Pete Caluori (pcaluori@hotmail.com), September 12, 2001.


Hi: I kept some Kodak Rapid Selenium sitting after an absence, or lapse I suppose, of too long from my darkroom, opened it up and it looked like vinager and oil dressing and smelled like rotten eggs. Is this common? What did I do wrong? It was only sitting for a few months. I also am afraid to dispose of it now. Thanks. Dean

-- Dean Lastoria (dvlastor@sfu.ca), September 14, 2001.

Are you sure that toner that went bad is selenium toner? The rotten egg smell sure points to a sulfide toner, i.e. sepia or the like. I have a gallon of selenium toner that I have been replenishing, filtering and reusing for more than 2 years and it shows no sign of degredation whatsoever. Regards, ;^D)

-- Doremus Scudder (ScudderLandreth@compuserve.com), September 16, 2001.

Yea, Kodak Rapid Selenium. I checked the bottle. It works just like the other bottles, except I kept this longer in 1:10. I don't own any sepia. Maybe the water caused it to curdle, or something. Most odd though. I'll give it a second chance though, as one shot on selenum seems like it is probably not great for the sewage system. Do you think the old stuff is safe to flush? or should I let it evaporate out ... any thoughts would be apreciated. Dean

-- Dean Lastoria (dvlastor@sfu.ca), September 17, 2001.

Dean, I guess you’ve confused the two odors, may be because you saw the rotten eggs very long times ago :)

The rotten eggs have the odor of sulphuretted hydrogen (hydrogen sulphide). The _sulfide_ toners (e.g. sepia toner) can have the same odor, Doremus is right.

The _selenium toner_ has the odor of ammonia, -- also an odor nasty enough, but different from sulphuretted hydrogen.

My selenium toner solutions live indefinitely long. I replenish it sometime, and the only changes are the black solid particles that can be filtered, as Pete Caluori noted above. If your solution shows any coagulation, suspension or other changes in the consistence of the solution, then I think it is damaged, probably with a sort of bacteria, and should be discarded. I suggest dilute it several times and pour out to the sewage system.

Regards

-- Andrey Vorobyov (AndreyVorobyov@mail.ru), September 28, 2001.



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