Do I need the pre-bleach?

Discussion in 'Color: Film, Paper, and Chemistry' started by R Paul, Mar 31, 2014.

  1. R Paul

    R Paul Member

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    Well I went out and ordered up some Kodak e-6 chemicals before they vanished. I picked up 1st dev, reversal bath, color dev and fixer. I mix up my own bleach (quinone),so I figured I didn't need the pre-bleach, since that works with the Kodak bleach.
    Now am I right in this, and do I rinse between the color dev and the bleach,or go straight through? I also have the starters for the developers,so that's ok

    Thanks
    Rob
     
  2. Jim Taylor

    Jim Taylor Member

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    Hmm... from what I understand the pre-bleach is used because the formaldehyde in the stabilizer was switched out due to exposure control regs. Hence stablizer became 'final rinse' (photo-flo and miconazole).

    I believe the pre-bleach now contains some chemistry that generates the formaldehyde 'in-situ' and thus is needed for maximum longevity of the resulting chrome.

    I guess I'll be corrected if wrong! :smile:
     
  3. R Paul

    R Paul Member

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    I use formalin in the final rinse, so I should be ok. I had forgotten about what it actually did. I am pretty sure PE mentioned it somewhere.
    Thanks
    Rob
     
  4. mts

    mts Subscriber

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    you should follow both first and second developers with a stop containing both acetic acid and bisulfite, and follow the stop with a rinse to eliminate possibility of contaminating the following solutions, and you must not use the same stop bath for both. That is, you need to have a first and second stop bath.
     
  5. Rudeofus

    Rudeofus Subscriber

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    Common E6 bleaches are very benign and, according to patent literature, will speed up if you use a prebleach. There's a good chance that you won't need it with your (much stronger) Quinone bleach, especially if you provide another source of Formalin. Read here about the purpose of Formalin in E6 processing.
     
  6. R Paul

    R Paul Member

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    The way I do E6 is from Kodak except I use a quinone bleach ( I think you gave me the formula). It has the 1st dev then a 2min wash with water, reversal bath, color dev,prebleach,bleach,fix ,wash and then stabilizer with formalin. I was thinking of substituting a similar water rinse between the CD and the bleach especially if the prebleach is only taking the place of the formalin rinse at the end. I would like to keep it as simple as possible.
    Rob
     
  7. R Paul

    R Paul Member

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    That would be good. So at worst I would have to extend the time in the bleach. I have had to re-run the bleach and fix steps at times, I think due the bleach aging. I use Photo-flo /formalin mix that PE recommended as the last step. It does pack a punch though especially indoors. I usually hang up the films in the evening and quickly retreat upstairs until the next day.

    Rob