Divided D76 precipitate

Discussion in 'Darkroom Developing and Printing' started by Lew, Feb 18, 2004.

  1. Lew

    Lew Guest

    I've just had my Formulary dD76 mixed for a week. Sol A has a dirty,
    brownish, snowflake sized precipitate in it. Has anyone else seen this? Is
    it normal or what?
    -Lew
     
    Lew, Feb 18, 2004
    #1
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  2. Did you use tap water?

    Martin
     
    Martin Jangowski, Feb 18, 2004
    #2
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  3. Lew

    Lew Guest

    Yes, but here in Brooklyn, NY the tap water is exceptional & I've never had
    any problems over the years with a wide variety of chemistries.
    -Lew
     
    Lew, Feb 18, 2004
    #3
  4. Lew

    Dan Quinn Guest

    Speaking of ALL photographic solutions, I can not think of ONE
    instance in which particulate matter is a contributing ingredient in
    the working solution.
    With repeated use some solutions do generate a little sludge. Divided
    D76 should have no precipitate, A or B.
    Just a thought; how much film got "mixed" into part A? Dan
     
    Dan Quinn, Feb 19, 2004
    #4
  5. Lew

    Lew Guest

    Dan:
    You're right, I really don't know whether it's precipitate or not. The
    solution was clear while unused. After 2 rolls of film the gunk appeared. I
    filtered a quantity to use today and the results look fine. Still like to
    know what's happening, though.
    -Lew
     
    Lew, Feb 20, 2004
    #5
  6. As Martin suggested, this is what normally happens when using the
    published formula of D76 or the alike made up with tap-water. First
    they are clear, after developing a roll or two you get some
    precipitate in the solution.

    I'm using Barry-Thorntons Two-bath (a metol/borate formula) this way
    with no ill-effects so far but this may depend on the rest of the
    processing conditions. Therefore, I would recommend to use distilled
    water to make stock as well as working solutions that do not contain
    any sequestering agents.
     
    Stefan Kahlert, Feb 20, 2004
    #6
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