Affect of temperature on fixer

Discussion in 'B&W: Film, Paper, Chemistry' started by bobwysiwyg, Jan 15, 2013.

  1. bobwysiwyg

    bobwysiwyg Subscriber

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    I've been using fixer time (fresh fixer by the way) as documented by Kodak. I wondered though, does temperature alter its ability to clear based on temp similar to the affect temperature has on developer?
     
  2. Sirius Glass

    Sirius Glass Subscriber

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    I would thing that as the temperature of fixer drops from 68°F [20°C] that the reaction time increases, but not a great deal. I would think that even with the solution ionization lowering the freezing point, that at 23°F [-5°C] that the reaction time would be much s-l-o-w-e-r.
     
  3. Gerald C Koch

    Gerald C Koch Member

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    Fixing is a mainly diffusion controlled reaction so temperature should not have that great an effect on it.
     
    Last edited by a moderator: Jan 15, 2013
  4. georgegrosu

    georgegrosu Member

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    I believe diffusion have an important role in photographic processes.
    Fixer is a total reaction and temperature and time are not critical.
    Fixer time is made during the clarification of the film plus
    time required for chemical products formed to diffusion the film in fixer ( x 2 time of clarification).
    It is best to follow the prescribed temperature.
    From a practical standpoint, plus or minuc few degrees C for fixer is not a catastrophe.
    A better agitation of solution fixer can compensate for the absence of several degrees.

    George
     
  5. bobwysiwyg

    bobwysiwyg Subscriber

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    Thanks for the replies everyone.
     
  6. Nicholas Lindan

    Nicholas Lindan Advertiser Advertiser

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  7. EASmithV

    EASmithV Member

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    So, if one were to do a bleach bypass on some E6, they would not heat the regular fix?
     
  8. RalphLambrecht

    RalphLambrecht Subscriber

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    there is a well-known ilford chart showing the dev time change according to temperature, but it does not follow the arrhenius equation;does anybody have an idea why?btw the ilford chart works very well in my experience.
     
  9. ic-racer

    ic-racer Member

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  10. Aristotle80

    Aristotle80 Member

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    I have an important warning about Kodak's liquid fixer concentrate and cold temperatures. For a time I had my photo chem in a backyard shed with no climate control. It dipped into the 40s for around two weeks. The next time I checked the chem the fixer was destroyed. (The developers were all fine.) A thick sludge precipitated out of solution and it looked so funky I wasn't confident about using it again. I tried stirring up the sediment but it didn't remix. The concentrated fixer was unmixed and uncontaminated since I don't dilute it for use all at once.

    So while temp doesn't drastically affect fixing times, be careful about cold storage conditions.

    (I'm not a chemist and I don't even play one on the internet. I've done BW constantly since the 90s and I'm generally pretty careful with my process. It's the only time something like that has ever gone horribly wrong for me.)
     
  11. Gerald C Koch

    Gerald C Koch Member

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    Diffusion controlled reactions can be very complex. One must take into consideration among other things the shape of the ions or molecules, their electric charge, the composition of the substrate, etc. A molecule containing a bulky structure such a tertiary butyl group will diffuse slower than one containg a methyl group