I'm looking for ideas to extend the shelf life of open film developers. I ran a search and found a suggestion to store developers under nitrogen (available from wine stores). Has anyone tried storage under vacuum? I was considering storge in old, and properly labeled, wine bottles. I could then use a vac-u-win pump to remove air. Anyone tried this?
Sounds like too much work for me.
When I first got into photography, the recommendations were to either use accordian-style bottles that could be squeezed to eliminate air, or else drop glass marbles into partially used bottles to displace air. Now, to be fair, in the 1970s a lot of photographers did color work in personal darkrooms, and color chemicals had notoriously short shelf lives. I don't think there was every as much of a concern for black and white chemicals.
Accordian bottles are fine in theory, but the fact is that the tendency of plastic to breathe offsets any benefit from squeezing out the air. And marbles - yeah, that works but its a PITA.
Frankly, the practice I have adopted (after about 30 years of this stuff) is to treat film and paper developers differently. I purchase liquid concentrate developers (Sprint or Ilford for paper, HC110 for film). The manufacturers provide these in plastic bottles, and in the case of paper developers, I leave them in the manufacturers bottle until I dilute them for one-shot use.
Also, in the past it was quite common to be able to purchase developer concentrates in one gallon quantities. That's really hard to do now - the one shop in this area that carries chemicals at all stocks only quart quantities, with an occasional half-gallon bottle sneaking in by mistake. While this practice means more frequent runs to the store, the fact that the concentrate is in a smaller quantity means that it gets used faster.
Also, in the past it was far more common to mix developers from powders. That had the advantage of extending the shelf life of the chemicals in the store. But in spite of the recommendations to stir when mixing, the temptation was always to mix in big jug, and to accellerate the process of mixing by shaking - and that puts more oxygen into the ehcmical than storing it in a partially filled container will ever do. So the fact that the chemicals more frequently come as liquid concentrates also reduces the concern today.
In the case of HC110, I mix the syrup concentrate to make a stock solution. Several years ago, I mistakenly mixed the concentrate with twice as much water as was needed, but I found that I preferred that dilution, so that's the way I do it regularly now. I store the stock solution in one quart colored glass bottles, filling them all the way to the top. The last (fourth quart) in the gallon of stock goes into a black plastic bottle, and is the first to be used. So the stock solutoins remain sealed in glass and with no air unitl the time comes to start using that quart, and then its used quickly enough that the small amount of oxydation that does occur because there is air in the bottles doesn't do any harm.
Certain chemicals might really benefit from the treatment Robert is talking about. Dokumol and Ilfosol S concentrates come to mind. I stopped using those because I couldn't use them fast enough and I was too lazy/busy to pursue it.
I don't go to the trouble of the marbles, sprays or sealing stoppers. I have found that going to glass bottles has solved the problem economically. Suppliers of wine makers here in Greece offer a variety of bottles with well sealing stoppers that have worked for me. Obviously you won't be able to find the same elsewhere but someone must still sell glass where you are. I haven't even bothered with colored glass because where I have run across it, it is signifiacantly more expensive. I just figure that my darkroom is dark most of the time anyway.
Like Monophoto, I have moved to chemicals that last- Ansco 120 and 130, Thornton's 2 bath, and Prescysol make up the bulk of my paper and film developers and I wear them out before they die.
thoughts about ready to go stock solutions and other storage options
http://www.apug.org/forums/forum37/32094-propylene-glycol.html discusses using prop glycol. I have used this, and it works. I hear what you are saying about open developer, ie. ready to use as well.
'Private preserve' does the job well to discourage aerial oxidization.
I found a source of a cheap small nitogen tank, and an regulator off e-bay to finish the set up, so no more private preserve cans, though they do last a long time. I use the nitrogen for home food preservation as well. Apples from my tree, for example, last a very long time - like from October til February before they begin to soften, when they are packed in 2.5l or 5l poly pails and gassed with nitrogen before puting the lid on
Mixing develoipers with distilled or reverese osomosis purified water is a good start. Vigourously boil it for a few minutes in a covered pot, and let it cool while the cover is on..doing this a few days or weeks in advance, an storing it in glasss jugs works well.
This boiling drives dissoved gasses, which include oxygen off. Developers are oxidizers, and are happy to get oxidized from disoved gasses as the film/paper we want them to work on.
Try to mix without driving air into the solution; I found a magnetic stirrer at surplus, and it make the job of controlled stirring a dream. Mix well, so all ingredients are well and trully fully dissoved. If this is done then the resulting solutions can be stored in the fridge without things dropping out of the solution as crystals. Cooling the solution slows down the reate of any cheical reaction, self oxidization included.
Keeping the product in almost full glass bottles, on a dim place, or with amber glass as the bottle works to keep the energy of light from setting the solution going, and the glass keeps air from migrating through the walls if otherwise plastic bottles.
Once used the developers do not keep as long as 'virgin' solutions. The use adds elements that may be oxidized to the mix, and they seem to be able to aid non-oxidized components to move along to an oxidized stae as well.
I've found the use of glass containers to be helpful - the other solutions so much less so as to be unworthy of the effort. I really believe a large part of the problem is the plastic bottles they sell in camera stores. The plastic bottles the manufacturers use for stock Rodinal and HC-110 seem to be fine. All of this is from my experience - maybe a chemist has a real explanation.
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The best method of keeping chemicals fresh for a long time is one I learned from physicist/photographer Ctein: Place a cut sheet of the original Saran Wrap over the mouth of your amber bottles, then screw the plastic cap over it tightly. I've had film and paper developers last almost a year with this method. Only the original Saran wrap will work--don't buy any others.
The solution to your problem is to make more photographs. The shelf life problem disappears. ;>)
I've just about everything in Amber Glass Boston Rounds
Originally Posted by tbm
equipped with Polyseal or Polycone caps. Those are screw
caps with PE cork inserts. Snug up good.
Shop for, glass boston rounds . Not expensive. A world wide
laboratory storage standard. Dan
Vacu-Vin stopper and hand pump work very well for developers. You can use some 1.5 and 0.75 liter wine bottles to store developer solutions. They also make jars that work with same hand pump and they work well for storage of hygroscopic and/or oxygen-sensitive dry chemicals.
Recyclable beverage containers?
Does anyone here have any thoughts about using the recyclable plastic pop (aka soda) bottles? Would there be any advantage to using the Seven-Up (green) bottles as compared to the cola (clear) bottles?
My storage space is not accessable to anyone but myself and my wife.