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  1. #11

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    The developer package I deal with contains 4 set of Part A, B and C. Each set is for making 10 liters of C-41RA replenisher. Each time I mix a set of the chemicals to make 10 liters of it. I basically store that much of liquid in 3 gallon sized bottles so the 3rd bottle is always partially filled. Along the way of using the developer replenisher there is no way I can always keep the bottles full. It is a hassle to divide the liquid into smaller bottles so that I could fill each of them full of it with no air in the bottles. Even if I could do that there would be a constant worry in mind that the liquid might not last long and by the time I get to use them only to find the juice has turned brownish.

    The availability of the CD-4 in powder form I am enabled to find and buy the largest and much cheaper (per unit of volume) developer package. I store the mixed incomplete C-41RA replenisher (Part C excluded) in gallon sized bottles. I never need to worry about if the bottles are full or not. It will last for years. I pour as much (or as little) as I need any time each time to use it. All I need to do is to add the starter per the instruction from Kodak and the CD-4 powder to it. My cost of processing per roll of films is way down and there is so much more fun to shoot films now knowing that I will get quality negatives always. By the way I own a Jobo ATL-2300.

  2. #12
    AllanD's Avatar
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    mtjade2007 Thanks for the idea!
    Heat or light; it depends on your sensitivity.

  3. #13
    Athiril's Avatar
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    Now if I can only get someone to mail me some CD-4!

  4. #14
    Rudeofus's Avatar
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    I am quite surprised to hear that CD-4 concentrate goes bad so quickly. Others have reported 3+ months working solution life, with lots of film processed in that time. What also surprises me is that nobody has mentioned protective gas as a way to keep oxygen sensitive liquids for a long time. People have successfully used nitrogen, butane or lighter fuels, and for those who do not want to mess with these, there is Tetenal Protectan in a convenient spray can for the same purpose.
    Trying to be the best of whatever I am, even if what I am is no good.

  5. #15

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    Here is a web page that shows a plastic comparison chart in which the transmission rate of oxygen, moisture, CO2, etc. through the plastic can be compared. PET is much better than HDPE int erms of oxygen transmission rate but HDPE is better in moisture transmission. It seems HDPE bottles are not as good as PET bottles in storing developer. However, most plastic bottles sold for photochemical storage are HDPE bottles. I think coke bottles are PET because they are as transparent as glass. I have heard that JOBO bottles are very oxygen proof despite they are HDPE bottles.

    http://www.alphap.com/basics/compare.html

  6. #16
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    This method can work, but the sulfite level will be quite a bit off, as a large portion of sulfite is in the developing agent concentrate. Since sulfite helps control color purity in color developers, you can get contaminated colors.

    It can also reduce sharpness and increase contrast.

    PE

  7. #17
    Rudeofus's Avatar
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    If the relevant CD part indeed contains CD-4 and Sulfite only (and the MSDS suggests this, too), one could look at a C41 recipe to find the proper quantities, e.g. here. This would indicate somewhere between 5 and 5.5 g/l CD-4 and 3-4 g/l Sodium Sulfite.

    However, C41 CD concentrates don't contain Sodium Sulfite, they contain Sodium Metabisulfite to keep pH low. Based on molar weight, you'd need only 0.75 times the amount of Sodium Metabisulfite, which means a proper substitute for that CD component would add 5.3 g/l CD-4 and 2.64 g/l Sodium Metabisulfite.
    Trying to be the best of whatever I am, even if what I am is no good.

  8. #18
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    Actually, the CD4 concentrate is an adduct of Sulfur Dioxide gas and CD4 (an acid and a base) which together act as two ingredients in the mixed developer and adjust the pH. This method is also used in making HC110 where HBr and SO2 are bubbled through the TEA to make the adducts which then form the Bromide restrainer and SO3 preservative in the mixed developer.

    PE

  9. #19

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    Thanks for the comments from PE and Rudeofus.

    I just looked at a Part C bottle of my Kodak C-41RA developer replenisher. It says it contains CD-4 and sodium bisulfite. Sodium bisulfite is very cheap and is available from Photographers Formulary too. So can I substitute Part C (it's gone bad anyway) with 5 grams of CD-4 and 3 - 4 grams of sodium bisulfite per liter?

    I tried 5 grams of CD-4 and no sodium bisulfite. I knew the Part C has something else (now I know it is sodium bisulfite) in it. But the negatives came out OK to me. I even reused the developer 3 more times with no problems.

    I am not a person with chemistry background. Substituting Part C with CD-4 and sodium bisulfate is simple to me. But if it has to be more complex than that such as dealing with PH adjustment, etc. It would be a dean end to me.

  10. #20
    Rudeofus's Avatar
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    mtjade2007, the Sulfite/Bisulfite doesn't work so much as an oxygen scavenger and developer protector. It reacts with oxidized developer and therefore does two things: first, it prevents an oily precipitate if the CD-4 in the concentrate becomes oxidized from storage. Secondly, it competes with the color couplers of your film for oxidized CD-4, which means it lowers contrast. Obviously you won't see the oily precipitate if you mix your dev with fresh CD-4, but I've seen it with older CD-4 powder.

    If you don't enlarge your negatives optically but scan them, the scanner software will hide most developments problems, so you may not see that your negs are off.
    Trying to be the best of whatever I am, even if what I am is no good.

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