Hazy Precipitate in First Rinse Water for Prints

Discussion in 'B&W: Film, Paper, Chemistry' started by John Irvine, Aug 17, 2008.

  1. John Irvine

    John Irvine Member

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    I slide my prints from the fix into a tray of water and then transfer them to the wash tank. Lately, I've noticed a light haze forming in the wash tray after several prints have gone thru. The last time the tray stood full overnight and I noticed the haze was settling to the bottom. I don't think it is a problem because the print goes from there to a moving water wash and I doubt anything is left on the print. But I am curious about what's going on.

    The paper is Ilford MG IV RC and the fix is common Kodak something. The water is chlorinated well water, probably a little acidic, and maybe some iron, although it is not evident.
     
  2. fschifano

    fschifano Member

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    Kodak powdered fixer with hardener or one of the liquid fixer concentrates with a hardener added? If so, that's perfectly normal. The hardener needs an acidic environment to remain in solution. If I recall correctly, the PH needs to be about 4.5. Tap water, even if it is a little acidic, might be around 6.5 or so and is not acidic enough. So the hardener carried over with the fix into the wash drops out of solution. The hardener is usually a form of alum.
     
  3. Ian Grant

    Ian Grant Subscriber

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    It's worth noting that Ilford don't recommend using a hardening fixer for films or paper. Using a hardening fixer also makes it more difficult to tone prints.

    Ian
     
  4. John Irvine

    John Irvine Member

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    It is Kodak powder with hardner. I guess the hypo solution is acidic enough not to cause the precipitate. I need to go read a bit about why and why not use hardened fix.
     
  5. fschifano

    fschifano Member

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    Correct. When you move the hypo (with hardener) laden prints to a clear water bath, you are introducing the hardener to a far less acid environment. As a result, the hardener precipitates out of solution because the ph of the clear water is too high.