Amidol Stock Solution Shelf Life

Discussion in 'Contact Printing' started by bmac, Jul 6, 2003.

  1. bmac

    bmac Member

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    What is the shelf life of Michael's Amidol formula when kept in a tightly closed bottle (minus the amidol)
     
  2. c6h6o3

    c6h6o3 Member

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    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.
     
  3. Donald Miller

    Donald Miller Member

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    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.
     
  4. bmac

    bmac Member

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

    juan Subscriber

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    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
     
  6. David Vickery

    David Vickery Member

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    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.
     
  7. Jorge

    Jorge Inactive

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    I would guess that if you freeze the solution it would keep for a long time, then just thaw and add the amidol.
     
  8. c6h6o3

    c6h6o3 Member

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    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.
     
  9. avandesande

    avandesande Member

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    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.
     
  10. Michael A. Smith

    Michael A. Smith Subscriber

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    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
     
  11. bmac

    bmac Member

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    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