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  1. #11
    Photo Engineer's Avatar
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    I would not dilute a C41 or E6 bleach to the wrong concentration. I would be careful using C41 bleach for E6, as the pre-bleach introduces a precursor to formalin and some other goodies which are to be activated by genuine E6 bleach. IDK if C41 bleach will do this properly. Therefore - watch out.

    PE

  2. #12
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    Quote Originally Posted by AlbertZeroK View Post
    I want it to last longer.
    You have 55 L of the stuff, and each 3.8 L of working solution (2.8 L of concentrate) will last you for 120 rolls, without regeneration. This means that you have enough bleach to process over 2,350 rolls of film. Even if you only use it to half it's capacity, you have enough for almost 1,200 rolls. I'd look to save your money in other areas, most importantly shooting a higher percentage of "keepers." Try not taking a shot unless you really think you are going to want to print it. Stretching you chemistry is not a good way to gain economy IMHO...especially with the sensitive color processes, as opposed to b/w.
    2F/2F

    "Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."

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  3. #13

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    Oh my god, why one shot???

    Bleach is not only the most expensive part in Processing but luckily the most stable part too.

    If you do have minilab chemicals they are probably replenishable. Assuming a replenishing rate of 50 each 135 / 36exp. Film (which would be indeed very high) these 55 Liters (of replenisher) would be good for about 1100 films!! I think because of that amount I just could not imagine, how thinking about dilution to increase the “mileage” would make any sense … (sorry)

    I would call this a lifetime supply, don’t toss it.

    Simply try it with extended times for E-6 processing too; if you are in luck your phototerm chemical-saving-problem will be solved this way round.

    Regards Stefan

  4. #14
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    I agree with replenishing/regen the C41 bleach.
    It is getting hard to come by and shipping the stuff is even worse.

    Stefan,
    do you know anything about adjusting PH of used bleach when regenerating?
    I had a datasheet for the Bleach III regenerator that I think I saw this but now I can't find it.
    (it's not the readily available tech pub for this product)
    Maybe I'm being unnecessarily paranoid.

    I seem to remember you needed to get the regenerated stuff in the mid 6.4-6.7 range but I am guessing and plan to use the Kodak Flexicolor Bleach III Regenerator soon.

  5. #15
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    Bruce;

    I don't remember the pH of Bleach III, but the old bleach was about 6.5.

    In any event, the pH is adjusted with Ammonium Hydroxide or Acetic Acid. Both can be had or made up to equal concentrations. I would use the 28% NH4OH and 28% HOAC for this to get to the right value for the bleach you are using.

    I posted some formulas here for the original bleach. You can use either of the two methods.

    PE

  6. #16
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    PE.
    I was hoping you'd see my distress

    When I was researching the regen I came across some old patents and also some datasheets and these all mentioned a PH adjustment was needed.

    I don't think the main Kodak TechPub for the Bleach III regen mentions it though.
    Maybe the regenerator has this adjustment built into the formula.
    I plan on testing before I use the regenerated bleach for anything decent obviously.

    Thanks as always.

  7. #17

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    Bleaches tend to work better / faster in slightly acidic milieu, My mydoneg air bleach III shall be at pH 4.50 (+- 0.2) for the seasoned solution. Because of slightly over replenishing it dropped to around pH 4 if I measured it once. Increasing the pH again to pH 4.5 with NAOH solution made no visible different at all. I decided to let it go now…

    Again, this is is only valid for my used products

    Kodak bleach III (seasoned Tank solution) should be around ph 4.5 and 5 too, newer sources say pH4,75 (+- 0.25)

    Google for Kodak cis-61 “Specific-Gravity and pH Measurements of KODAK Processing Chemicals”. Depending on the year of that data sheet you can get slightly different values.

    Regards Stefan

  8. #18
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    The pH of the C41 bleach has been varying over the years to match the film dyes. At one time, if the bleach was too acidic, you could set up a redox reaction between the bleach, the silver and the cyan dye and end up with a leuco (colorless) form of the dye. At that point, your negatives (or slides if you tried this with E6) would be too red. To fix this, you would then have to treat with a ferricyanide oxidizing bath to reform the cyan dye.

    So you see, this is not a simple matter - playing with your bleach and the bleach pH. I suggest measuring the pH of fresh bleach III and then as you work, you adjust the pH back to that value!

    PE

  9. #19

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    The other reason for one shot is that I want to pay around with developing movie film. my calculations with the photo therm, I should get over 600 rolls with my supply, which is far less than I'd like, considering I have enough developer for 80L of developer.

  10. #20
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    Quote Originally Posted by Photo Engineer View Post
    I would not dilute a C41 or E6 bleach to the wrong concentration. I would be careful using C41 bleach for E6, as the pre-bleach introduces a precursor to formalin and some other goodies which are to be activated by genuine E6 bleach. IDK if C41 bleach will do this properly. Therefore - watch out.

    PE
    I've tried it. You get left with brown film + streaks, which then you need to bleach with fresh beach.

    With C-41 bleach (Flexicolor Bleach III) you have to rinse/wash after colour developer, skip the pre-bleach, do the bleach, and run a stabiliser at the end.

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