Freezing E6 & C41 chemistry?!

Discussion in 'Film and Processing' started by discpad, Jan 13, 2006.

  1. In Rob Landry's post he wrote:
    I store my E6 working solutions (in plastic bottles) in my deep-freeze at -22 Celsius. Froze a bunch over 6 months ago and just processed some film last weekend with great results; no noticeable changes with a test roll. I can't imagine a whole lot of oxidation occurring at that temp.
    I mainly freeze my chems for convenience; it's a lot easier (and more accurate) to mix the entire 5L kit at once and freeze into 1L sized bottles than it is to try and draw off small amounts of chems from the concentrates every time I want to process. When I processed last weekend, I simply took the 6 frozen bottles from the deep-freeze, placed them in the sink with hot water, they thawed out in 45 minutes and I was ready to process. No need to haul out my graduates, and other related mixing crap and no need to try and evacuate air or find smaller bottles for the concentrates; easy as pie.
    Now, this looks promising for E6 first & color developers, and C41 developer. [I toss reversal & pre-bleach; while fixer is used for other stuff and bleach has an air bubble stone in it.

    Paging Ron Mowrey!

    Dan Schwartz
    Cherry Hill, NJ
    Click here to visit my home page!

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  2. Dan;

    "Air bubble stone"????? IDK about that one. Please explain...

    As for freezing diluted processing solutions, it is quite reasonable as long as everything goes back into solution when thawed. It seems to me that the organic chemsitry would 'oil out' when frozen so you have to watch for that, and once formed, the oil will not redissolve easily, if at all.

    This would be particularly true of color and B&W (first) developers.

    All of the solutions could be frozen, but I wouldn't want to use glass containers, I would leave an air space at the top filled with nitrogen if possible, and I wouldn't want to spill or leak into the freezer. Beware of any chemical contamination and use air tight bottles to prevent spillage.

    If there were any spillage or leaking in the freezer, I would consider it unsafe for storage of edible food, especially reversal bath and stabilzer, not to mention the developers.

    Ron Mowrey
  3. Ahh, I wasn't expecting an answer quite this quick! :)

    First, an air bubble stone is what you find in a pet store to plug on to the end of an aquarium air hose... Call it a 69 cent sparger for the bleach!

    Next, since I toss E6 reversal & pre-bleach baths, that will save space in the freezer. Also, I use a 2% formaldehyde solution in a 5 gallon bucket, and then I simply toss in the E6 or C41 concentrate depending on what I'm running; then I put the lid on the bucket for next time.

    Now, a question: You wrote "It seems to me that the organic chemsitry would 'oil out' when frozen so you have to watch for that, and once formed, the oil will not redissolve easily, if at all."

    OK, what is "Oiling out?"

    Thanks a bunch! Dan
  4. Many organic chemicals have limited solubility in water, acid or base.

    Developing agents are basic and so are developer solutions. You add the developer as an acid and then neutralize it to make sure it dissolves properly. If you chill the solution, it can come back out again, but since it is now 'impure' being mixed with other ingredients, the melting point of the free base of the developer is lower than it was, and so it is a liquid.

    Pour some oil on water and you see what you might see from developing agent oiling out. Eventually, since it does not carry any sulfite with it, it will 'tar' or turn to a black solid tar floating on the surface. The developer is useless until you redissolve the oil, and if it 'tars' it is ruined totally.

    Ron Mowrey
  5. Ron,

    I have not had any of the "oiling" that you spoke of and my processed film turned out fine. Upon thawing, I rolled the bottles across the counter to make sure the chemicals were mixed and everything looked as it should. I'm planning on processing again soon, so I will keep an eye out.
  6. Just an update.

    I have just finished processing 8 sheets of 4x5 Velvia, 1 roll of Provia and 2 rolls of Elitechrome and everything looks great. Chemicals did not exhibit any oiling and no precipitates were observed.

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