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  1. #21
    RPC
    RPC is offline

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    After mixing the formula the pH is too high, even without HAS, so I just add whatever acetic acid I need to bring it to normal.

  2. #22
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    The standard procedure to adjust pH is to use Sodium Hydroxide or Sulfuric Acid depending on the direction you want to move. Neither developer (C41 or RA4) should contain Benzyl Alcohol. HAS extends shelf life and also it prevents tar formation and it helps keep Dmin low.

    PE

  3. #23

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    By the way -- what is the purpose of potassium (or sodium) chloride in the formula? And if the formula calls for sodium chloride, how much potassium chloride should be used in substitution?

  4. #24
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    The color paper emulsions are mainly AgCl emulsions and thus Cl ion acts as a seasoning agent and restrainer or antifoggant. The positive ion balance (Na or K) is probably important for balancing development, but I am not sure.

    PE

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