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  1. #1

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    What is the acid percentage of Kodak Indicator Stop Bath concentrate?

    I have a couple of old bottles of the concentrate but neither states the concentration. Is it 28%, or something else? I'd like to know so I can do some semi-intelligent experiments acidifying used alkaline fix for electrolytic silver recovery.

    Thank you.

  2. #2

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    Weight % - Component - (CAS Registry No.)
    Concentrate:
    85-90
    Acetic acid (000064-19-7)
    10-15
    Water (007732-18-5)
    < 0.1
    Bromocresol purple (000115-40-2)
    or
    Kodak indicator stop bath concentrate is around 95%
    You choose
    "There are a great many things I am in doubt about at the moment, and I should consider myself favoured if you would kindly enlighten me. Signed, Doubtful, off to Canada." (BJP 1914).

    Regards
    Bill

  3. #3

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    Closer to 95% or so.
    Bob

  4. #4
    Mike Wilde's Avatar
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    Is auto store sulfuric not more affordable?
    my real name, imagine that.

  5. #5
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    Acetic Acid is soooo much more gentle on the skin!

    PE

  6. #6
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    Couldn't agree more. Sulfuric acid is nasty stuff to be avoided if not absolutely necessary for a particular application or function.
    WYSIWYG - At least that's my goal.

    Portfolio-http://apug.org/forums/portfolios.php?u=25518

  7. #7
    holmburgers's Avatar
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    So diluted 1 to 63, does that mean a working stop bath is about 1.5% acid?

    What about vinegar, where does that lie?

  8. #8
    DWThomas's Avatar
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    Quote Originally Posted by holmburgers View Post
    So diluted 1 to 63, does that mean a working stop bath is about 1.5% acid?

    What about vinegar, where does that lie?
    5% is pretty typical.

  9. #9
    DWThomas's Avatar
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    Hmmm - I may have been less than clear there, vinegar is typically 5%.
    Last edited by DWThomas; 02-22-2012 at 09:47 AM. Click to view previous post history.

  10. #10

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    Quote Originally Posted by holmburgers View Post
    So diluted 1 to 63, does that mean a working stop bath is about 1.5% acid?

    What about vinegar, where does that lie?
    I have always mixed mine at 16ml/L which is 1.6% Kodak's recommended dilution. Your 1:63 gives you the same dilution.

    Gord

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