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  1. #21
    Ian Grant's Avatar
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    Quote Originally Posted by georg16nik View Post
    They give 2.0 - 5.0% for potassium hydroxide, so 11.8 is approximate.
    Also, there is no way my water and Your water to be the same pH and mineral content.
    This spring, the water in the pipes moved from 6 pH to 10 pH. I am usually distilling water but sometimes I just use filtered tap water when I don't wanna wait for a few hours for the distiller to round up..

    G
    The water's going to make no significant difference.

    The pH 11.8 of Calbe RO9/APH09 is not approximate, the way older R09 is made is to balance the developer so that there is no free hydroxide, at that point there is a very slight precipitation of p-Aminophenol free base crystals which is normal for this developer. That's been the case for over 100 years and only the later Agfa Gevaert version of Rodinal now sold as Adonal etc changed this.

    The difference in pH 11.8 of Calbe R09/APH09 and Rodinal/Adonal etc's pH 14 is large but is purely because the first relies on more developing agent at a lower pH with no free Hydroxide and the second on less developing agent and a sgnificantly higher pH due to an excess of Hydroxide.

    Ian

  2. #22

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    I have made various rodinal type developers. From my personal experience an excess of hydroxide shortens the shelf life of the developer.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

    ~Antoine de Saint-Exupery

  3. #23

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    Then, there might have been something with my bottle of APH09
    I got suspicious and even checked my pH tester, checked mixed solution in a lab, with a very high end pH tester as well, within the 1 hour time frame of mixing the solution..
    The only thing crossed my mind is, if I happen to have a batch of APH09 with early Adonal stuff poured inside.. hence the 13 ~ 14 pH.
    I have had mismatched stuff with Adox before but it was with film.. CMS in a canister of Ortho

  4. #24

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    Quote Originally Posted by Gerald C Koch View Post
    I have made various rodinal type developers. From my personal experience an excess of hydroxide shortens the shelf life of the developer.
    I have noticed darkening of the developer color towards dark brownish within 1 year or so. That is APH09 from one of the 1st batches.
    Besides the change in color - it worked well till the end..

  5. #25
    baachitraka's Avatar
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    It seems pH of Adox APH 09 & Adox Adonal have identical pH = 11.8, if those data sheets are correct.
    OM-1n: Do I need to own a Leica?
    Rolleicord Va: Humble.
    Holga 120GFN: Amazingly simple yet it produces outstanding negatives to print.

  6. #26
    Ian Grant's Avatar
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    Quote Originally Posted by Gerald C Koch View Post
    I have made various rodinal type developers. From my personal experience an excess of hydroxide shortens the shelf life of the developer.
    That's true however before WWII Agfa were testing long chain wetting agents and patened some which they found to have unexpected anti-oxidising properties. One of these is used in later versions of Rodinal, it was being used during WWII.

    This is one reason why the Agfa version of Rodinal with it's excess Hydroxide has better keeping properties than the Calbe RO9 developer.

    Ian

  7. #27

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    Yep, thou on the Adonal page there are 2 different .pdf's the second one, being very brief its saids shelf life: at least 6 months..
    http://adox.de/RODINAL.pdf
    Now, on the APH09 page its saids "Shelf life of concentrate: up to 50 years" http://www.adox.de/english/ADOLUX/AD...LUX/APH09.html

    In the age of the present day films, it might be not that much critical if the pH is 11.8 or 14. even thou that is more than 20 times more alkaline, thou as Ian said, temperature differences might shuffle the buffalo..

  8. #28
    Ian Grant's Avatar
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    Quote Originally Posted by baachitraka View Post
    It seems pH of Adox APH 09 & Adox Adonal have identical pH = 11.8, if those data sheets are correct.
    The Adonal datasheet is incorrect, the manufacturers datasheets Bayer/Agfa are more exact with the pH 14. It's still made in the same factory.

    Ian

  9. #29

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    Quote Originally Posted by Ian Grant View Post
    The Adonal datasheet is incorrect, the manufacturers datasheets Bayer/Agfa are more exact with the pH 14. It's still made in the same factory.

    Ian
    That is why I regularly check the pH of developer, fixer, water..
    pH is a logarithmic, so a difference of 1 pH unit is equivalent to a tenfold difference in hydrogen ion concentration
    Sometimes there are surprises.. 11,8 and 14 are quite a different league..lol

  10. #30
    baachitraka's Avatar
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    We can now draw a conclusion on choosing the developer for stand development. Can we?
    OM-1n: Do I need to own a Leica?
    Rolleicord Va: Humble.
    Holga 120GFN: Amazingly simple yet it produces outstanding negatives to print.

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