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  1. #11

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    Jerry,
    You have a good case re D-76, since it's pretty similar to Xtol, which I make last > 24 months by mixing in 10 500ml sealed bottles and it's not worth doing the work to make D-76 last >24 months.
    But generally, and I'm sorry, I didn't explain what I meant very well,it is an advantage to have long lasting developers as many can be made up to choose from ,eg, alongside this solvent developer Xtol occasional amounts of other developers can be used provided they last >24 months.
    So one can have a choice of Xtol, Rodinal,PMK Pyro and anything else can be made to last, I have used quite a few.Having a collection of long lasting developers is not strictly necessary but it makes film developing more interesting IMO.Anchell and Troop wrote a book about it.

  2. #12
    Ian Grant's Avatar
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    It's interesting that Kodak spent many years of research into improving D76 but they were stuck because it had become a standard with clones from many other manufacturers. Initially a cine film developer the industry required it's availablity around the world. Later it became a mainstay of professional labs asa well. Kodak did alter the buffering and it's almost certain Ilford did the same.

    The misnamed non Kodak D76H, (there was already a Kodak D76h MQ variant of D76), is really Haist alluding to the earlier 1927 Eastman Kodak Research Fine Grain developer.

    It used to be common to publish some formulae as one part or alternative much longer lasting 2 part solutions with the alkali in Part B.

    Sodium mmetabisulphite is used in some powdered developers to help protect the developing agents in powder or lquid form, this form should be used rather than the less powerful (antioxidant) form Sodium Bisulphite, it should also be reasonably fresh. It's used in a couple of Ilford powder developers.

    Ian

  3. #13

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    Hi Alan,

    Having a collection of long lasting developers is not strictly necessary but it makes film developing more interesting
    Ah, but one must avoid the sense of "interesting" as in the Chinese curse, "May you live in interesting times."

    There is also Ansell Adams' advice to thoroughtly learn one film and one developer before doing anything else. I currently use two developers, a Rodinal clone and HC-110. Over the years I have come to understand their benefits and problems. Both of these have a very long shelf life as a single solution. When using Ilford Pan-F I will add D-23 to tame this films contrast. I only mix what I will need.

    Your point of using multiple bottles is a good one and one often overlooked. You cannot have oxidation in the absence of oxygen. By avoiding partially filled bottles much of the problem is solved.

    Cheers from sunny Florida.

    Jerry
    Last edited by Gerald C Koch; 02-21-2013 at 02:10 PM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

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  4. #14

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    I might add to Ian's comment about Kodak being stuck with D-76 that when they chose to make a new developer intended for commercial processors (HC-110) this new developer had to duplicate as nearly as possible the results from D-76. They still couldn't get away from D-76!

    This developer would also solve the OP's problem. It lasts a long time (years) and is cheap. You can use it as a one shot diluted just before use. Easy and no mixing involved.
    Last edited by Gerald C Koch; 02-21-2013 at 01:58 PM. Click to view previous post history.
    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

  5. #15
    Ian Grant's Avatar
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    Gerald, you mention D23, have you tried D25 ? As you know it's the same except it has Sodium Metabisulphite.

    At a lower level it would have less affect on the pH, but still act as a preservative.

    Ian

  6. #16

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    Isn't it Sodium Bisulphite (Bisulfite) in D-25?

  7. #17
    Ian Grant's Avatar
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    Quote Originally Posted by Michael R 1974 View Post
    Isn't it Sodium Bisulphite (Bisulfite) in D-25?
    Depends which company publishes the formula, EK use Bisulphite, Kodak Ltd Metabisulphite. it more about the purity of the Meatbisulphite it seems to be manufactured differently in Europe, Kodak Bisulphite is a lower grade mixture of Bisulphite and Metabisulphite.

    In some formula the differences are not so important but as a preservative then it becomes more critical.

    I used Metabisulphite industrially and there was a significant difference, JT Baker produce and sell both, and the usage depends on how strong an anti oxidant is needed.

    Ian

  8. #18

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    Sodium metabisulfite Na2S2O5 can be thought of as a chemical container for sulfur dioxide. When added to water 1 mole reacts with 1 mole of water to form two moles of sodium hydrogen sulfite (sodium bisulfite). It is used because it is more stable as a solid than sodium bisulfite. The most common form of sodium bisulfite is therefore a near saturated solution known commonly as bisulfite lye.
    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

  9. #19

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    Ian, I tried D-25 many, many years ago but the development times were just too long. In a replenished system there was also significant sludging. At a lower pH its keeping properties are probably better than those for D-23.
    Last edited by Gerald C Koch; 02-21-2013 at 06:39 PM. Click to view previous post history.
    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

  10. #20

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    Quote Originally Posted by Gerald C Koch View Post
    This developer would also solve the OP's problem. It lasts a long time (years) and is cheap. You can use it as a one shot diluted just before use. Easy and no mixing involved.
    Thank you all for the discussion.

    Gerald, I don't have a problem. I've been a happy user of ID11 for many years and I go through 5 liters fairly quickly. I was just curious about the "problem" Anchell&Troop mention about D76 (i.e. rise in alkalinity and activity) and wondered whether there might be a solution. Personally, ID11 has always worked consistently for me.

    Recently I've started experimenting with home brews (simple MQ developers really) and after reading this: http://www.udmercy.edu/crna/agm/phenvitc.htm and seeing how the activity of commercial D76 remained fairly consistent over many months, I concluded that Kodak must have changed something in the original formula for improved consistency. So, if I *did* use the original formula, would I run into the "problem" said to be discovered by Haist in the 1920's and discussed by Anchell&Troop, was the motivation for my initial question.

    Regards

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