Amidol Stock Solution Shelf Life

bmac · Jul 6, 2003

What is the shelf life of Michael's Amidol formula when kept in a tightly closed bottle (minus the amidol)

c6h6o3 · Jul 6, 2003

An easier way: Measure out batches of the various chemicals and put them in plastic ziploc bags (the really little ones-the ones that aren't even big enough to hold a sandwich). I weigh out 3 or 4 printing sessions at a time this way. Then I just mix them whenever I print with amidol. I don't have to worry about shelf life and my chemicals are always fresh.

Donald Miller · Jul 6, 2003

I would agree with Jim's approach to amidol. I weigh and mix as I need to. The general concensus seems to be that Amidol will last about one day of printing. Possibly a bit into the second day. Those who claim that the developer is consistant in it's action beyond that point are few. As I said this is the concensus of opinion. I have not personally verified this myself. I don't know what the chemical reason would be since Amidol is supposedly not subject to effects of it's own oxidation.

bmac · Jul 6, 2003

I am talking about mixing up evrything besides the amidol, and then adding amidol right before printing... atill a bad idea?

juan · Jul 6, 2003

I've mixed a stock solution several times. Almost all of my darkroom work is on the weekends, and on one occasion, I mixed the stock solution, used some one weekend, and refrigerated the stock solution until the next. It didn't work - even if I developed Azo for three minutes, I got almost no image.

However, if I mix a stock solution and use part one night and the rest the next, it works fine. I notice no difference between prints developed on the two days.
juan

David Vickery · Jul 6, 2003

Hello, I would assume that it would not be a good idea to premix a stock solution-- even without the amidol. Because of the sodium sulfite's desire to turn into sodium bisulfite(I think that's what it converts to ??---there are others here who know this stuff a lot better than me). When we mix our ABC stock solutions we don't usually mix the B solution unless we know that we will be using it within a few weeks, as it changes. But the amidol stock would also have KBr and Citric Acid---would that stop the Na Sulfite from changing itself ?? I don't know, but I like the idea of using the little baggies to get organized.

Jorge · Jul 6, 2003

I would guess that if you freeze the solution it would keep for a long time, then just thaw and add the amidol.

c6h6o3 · Jul 6, 2003

Stock solutions of pyro film developers are nice because they obviate the need to heat the water, handle toxic powders with respirators, etc., etc., etc. any more than once in a while.

Amidol presents none of those problems. Just mix it when you need it. It keeps for at least a day in the tray and you can't exhaust it.

avandesande · Jul 7, 2003

I have used week old amidol solution. Your results aren't as good as fresh but its good enough for a proof or practice. After a week you start getting pink goop on your prints.

Michael A. Smith · Jul 7, 2003

All of the chemicals mix up at room temperature. Mixing before use should not take more than a couple of minutes. Suggest you do it freshly each time.

Michael A. Smith

bmac · Jul 7, 2003

will do, thanks. Trying it for the first time this weekend, and can't wait. Going to try some 8x10, 4x5 and digital negs.

Brian

Amidol Stock Solution Shelf Life

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