Agfa FX-Universal Fixer

Discussion in 'B&W: Film, Paper, Chemistry' started by Mark Layne, Oct 14, 2003.

  1. Mark Layne

    Mark Layne Member

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    Hi
    Having read that FX-Universal is an alkaline fixer I decided to try some.
    When I test it with a pH test strip it reads 'weakly acidic'
    Any thoughts on this

    Mark Layne
    Nova Scotia
     
  2. Bruce Osgood

    Bruce Osgood Membership Council Council

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    These are recommendations of working strength solutions provided by Ryuji Suzukia, a highly regarded chemist of B/W photography.

    developer (bw): pH ~9
    stop: pH 3-5.5
    fix: ~pH 5
     
  3. Robert

    Robert Member

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  4. Mark Layne

    Mark Layne Member

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    It was mixed with tap water

    Mark
     
  5. Robert

    Robert Member

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    Depending on what your water is like that could explain the difference in pH.
     
  6. john_s

    john_s Subscriber

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    I am not a chemist, but I would expect that a liquid fixer would be fairly well buffered against pH changes due to normal water variations. According to Ryuji Suzuki the measurement of pH of photographic solutions is difficult with pH meter unless you have a special probe. He does actually recommend indicator papers. I wonder if your indicator papers are good for such a strong mixture of chemicals. See

    http://silvergrain.org/Photo-Tech/experimental.html

    FX-Universal is supposed to be slightly alkaline, no more so than much tap water. It is not supposed to be conspicuously alkaline. It is sufficiently not acidic to give the obvious benefits of alkaline fixers (especially no SO2 odour) but not so alkaline that emulsion softens noticeably.

    As far as your indicator papers are concerned, I don't know why you got the reading that you did. What make/type are they?
     
  7. Mark Layne

    Mark Layne Member

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    On taking another look at this I checked the tap water and it does read acidic.
    Testing the undiluted fixer does give a weakly alkaline reading-just barely.

    The tap water does seem to give other problems. Arm and Hammer sodium carbonate dissolved in it gives copious precipitated sludge and does not develop Jand C 200 in the times recently posted by Sandy

    Mark
     
  8. glbeas

    glbeas Member

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    Have you had the water tested to find out whats really in it? Sounds like you need to mix all your chemicals in distilled water.
     
  9. Robert

    Robert Member

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    The carbonate is dropping out of suspension. That stuff likes to drop out.

    Just use distilled water to mix with.
     
  10. glbeas

    glbeas Member

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    Actually seems to me theres a lot of metals in the water and the sludge wouuld be metal carbonates. The sodium carbonate dissolves very readily. If distilled is not available maybe a bit of water softener to remove the metal sludging. Anybody know how that is handled if your system doesn't have a water softener?
     
  11. Aggie

    Aggie Member

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