Digibase C41 kit mixed chemical storage life.

Discussion in 'Film and Processing' started by tim_cokayne, Dec 11, 2010.

  1. Hi Forum,
    After a couple of years of processing my own B&W film I want to start processing my own colour film so I've purchased a Digibase C41 processing kit. I want to make up the full 1 litre of chemicals and store them in air- tight containers as I do with my black and white chemistry but am concerned about the shelf life of the mixed chemicals. Do any forum members know how long these colour chemicals can be stored?
    Thanks, Tim
  2. The directions with the chemistry should say? But generally ,like B&W, color chemistry doesn't have a long shelf life when mixed. Light tight, air tight containers are always optimum though.
  3. For smaller kits, really you should use it within days, not weeks or months.
  4. It's only a few weeks with the Digibase C41 chemicals as working solution. So it will be better to keep it as concentrate as long as possible. When using higher speed iso C41 films it's even shorter. The Bleach and Fixer can be kept longer. Just follow the instructions which are delivered by each kit.
  5. The mixed C-41 can last very long time. Bleach will last pretty much forever. The fix is second best. The developer needs care: make sure it's in air-tight container in a cool place. I just finished my stash of C-41 developer that I mixed back in April. I kept it in small juice bottles filled to brink, and stored in a fridge. So far, the longest I kept mixed developer was 6 months before running out of it. Perfect results, the chemicals look like new. I did mix it with distilled water which was boiled and cooled. The final rinse must be kept in concentrate and mixed right before use. Otherwise biological scum will grow in it.
  6. Thanks for your responses everyone. I was under the impression that c41 developer had a shorter shelf life when mixed to a working solution compared to B&W. I intend to shoot at least 1 roll of color 35mm film per week so having a litre of developer ready to use would speed up my work flow considerably as the temperature to mix the 4 part developer is higher than the working temperature.
    Am I correct in assuming that I mix to the full amount (1 litre as its a small kit) and pour the developer back into the air-tight bottle after each use and only use on a total of 12 35mm films? I always mix up either 300, 600 or 900ml of B&W chemistry (enough to cover 1,2 or 3 reels of 35mm in my Patterson tank) and dispose after each use, so this method of re-using the same chemicals is alien to me.
    Apologies for asking these questions but the instructions that come with the Digibase kit aren't that straight forward and are poor English translations from German. They are also geared for people using a Jobo processor but I intend to do it manually in a tank of water and an accurate thermometer.
  7. Just for anyone googling Digibase c41- The store I bought it from told me that the mixed developer only lasts a week.
  8. One week is a very safe limit. But for reproducible results it's indeed a good habit to use the working solutions C41 up within 2-3 weeks. So in that way it's a good idea to collect some C41 films for simmultanuous development.

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