Sharing Graduates & Cross Contamination

Discussion in 'Color: Film, Paper, and Chemistry' started by brianmichel, Jun 18, 2009.

  1. brianmichel

    brianmichel Member

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    So I'm currently setup for basic at home b&w processing, but I'm going to try my hand at the C-41 process soon and I have a question about using my b&w graduates that hold and mix my developer and fixer. I would like to just mix the color developer in my b&w developer graduate and my blix solution in the b&w fix graduate. I'm worried that these could cross contaminate the graduates when I go back to use them for a different process, i.e. getting color contamination in b&w and vice versa. Is this a legitimate issue to worry about, or will a nice thorough washing help avoid these issues? I would appreciate any insight into this, thanks!
     
  2. AlexG

    AlexG Member

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    Are your graduates made from glass of plastic?

    Sometimes my plastic graduates tend to leave a bit of residue even after a thorough washing. The Pyrex graduates always seem to never leave any residue.


    I've mixed C-41 chems before in both my plastic and glass beakers but never seem to have any problems though.

    Edit: Just remember to use different bottles to store your chemicals!
     
  3. brianmichel

    brianmichel Member

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    Sounds good, I figured that there would be some degradation over time with the plastic graduates, but glad to see I should be good to go in the short run!
     
  4. Photo Engineer

    Photo Engineer Subscriber

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    Use developer graduates for developer and blix and fix graduates for blix and fix. Use stronger bleach graduates for blix and fix as well, but give a good extra wash. Use separate graduates for stabilzer and photo flo solutions which are quite similar.

    Do not use plastic for developers of any sort. This is due to all of the organic matter.

    PE
     
  5. Tom Kershaw

    Tom Kershaw Subscriber

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    PE,

    Are you suggesting that all developer mixing should be undertaken in in glass beakers?

    Tom.
     
  6. David Brown

    David Brown Subscriber

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    Don't they all come in plastic bottles? :confused:
     
  7. brianmichel

    brianmichel Member

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    So plastic or not?
     
  8. Christopher Walrath

    Christopher Walrath Member

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    Mixing in plastic would be fine. As a rule I mix one shot/ one session chems so I store my opened stock in amber glass bottles just as a precaution.
     
  9. Mick Fagan

    Mick Fagan Subscriber

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    PE is correct from a pure technical point, however in a home darkroom we often make concessions due mainly to space, cost and being practical.

    I myself use Jobo graduates, they are plastic and virtually impermeable to contamination from photographic chemicals. If they weren't, then I would have been in trouble many years ago.

    I do though follow PE's advice regarding using a set of graduates for developers, another for bleach and fix solutions, plus another set for stabiliser and Photo-Flow solutions.

    I have mixed up E6, C41, B&W and a myriad of other kinds of solutions using about 12 different graduates. I did start to use glass about 15 years ago, but due to a lack of feeling in my hands and fingers, I started to drop things and started to break them, so I reverted back to my plastic graduates.

    I also use my Durst Printo paper processor for Colour negative paper prints, as well as B&W negative paper prints. I have switched back and forth over the last 18 or so years I have had the machine with no discernible problems. That doesn't mean that one could not measure a cross contamination, it is just that I haven't noticed any and none of my prints that have been processed have shown any problems, although from a scientific point of view, this practice would be unacceptable.

    From a home processing point of view, I would suggest you do whatever you can afford. If at a later stage you really swing into colour processing, then outlay some dosh and get another set of graduates and go from there.

    One point of view in this debate about single use graduates, are the film developing tanks available today. The great majority are plastic, very, very few are stainless steel. Virtually everyone switches from B&W to C41 to E6 to whatever in the same tank!

    Mick.
     
  10. Photo Engineer

    Photo Engineer Subscriber

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    You don't continuously reuse the plastic source bottles. They are usually discarded or reused for the same chemistry.

    PE
     
  11. Photo Engineer

    Photo Engineer Subscriber

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    Tom;

    Ideally, glass or SS should be used for developers which is what I do. Do what you wish dependant on economics.

    PE