Does bleach contaminate fixer?

Discussion in 'B&W: Film, Paper, Chemistry' started by Dave Krueger, Jan 25, 2012.

  1. Dave Krueger

    Dave Krueger Member

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    If I bleach prints in ferricyanide can I clear them in the same fixer I use after developing prints or does the bleach contaminate the fixer necessitating that I keep two dedicated fixer solutions on hand (one for normal use after developing and one for use after bleaching)?

    It's not like fixer is so expensive that keeping two baths on hand would be that much of a hardship, but I'm still curious about whether there's a chemistry-based reason for doing so. I don't normally bleach prints, but I plan to experiment with it soon, so any help answering this question would be appreciated.

    -Dave
     
  2. Existing Light

    Existing Light Member

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    I dont know if it "hurts" fixer, but if you have an extra tray to wash as much of the ferricyanide off the print before putting it in the fixer tray, that might be your best option :smile:
     
  3. RalphLambrecht

    RalphLambrecht Subscriber

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    i have the same issue.judt wash as much bleach of as you cnsndlrt it drain 9rip)off the print for 30s.alsostart evry prinying seesion with fresh fixer. and you'll be fine!
     
  4. Ian Grant

    Ian Grant Subscriber

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    The bleach breaks down in time in the fixer but ideally you don't want to contaminate your print fixer, so a good rinse first or keep a small amount of fixer aside just for this purpose.

    Ian
     
  5. Dave Krueger

    Dave Krueger Member

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    Thanks for the replies. I think perhaps my understanding of the bleaching process must be flawed. I will go back and look at some of my references tonight. I'm thinking mostly in terms of bleaching the entire print for a few seconds and then dropping it into the fix, repeating as necessary. I thought getting it into the fixer quickly was imperative, but it sounds like rinsing the bleach off before fixing is enough to keep it from getting away from you.

    I think I will just go ahead and mix up a batch of fixer for bleaching just to be safe. It's impractical for me to mix up fresh fix for every printing session because I usually print only a few 8x10s in a session.
     
  6. jeffreyg

    jeffreyg Subscriber

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    I'm curious as to why you want to bleach your (entire) prints. Why not make the best print you can and only bleach where and when necessary? Do it slowly and carefully. Try putting the print on a sheet of acrylic in the sink and apply a rather weak bleach solution to the areas to be bleached and quickly rinse. I would also have a separate tray of fix for after the bleach and then transfer to your regular fix tray. I like to have two fixes anyway. Don't be surprised or discouraged if you mess up some prints honing your bleaching skills.

    Good luck.

    http://www.jeffreyglasser.com/
     
  7. Dave Krueger

    Dave Krueger Member

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    My reason for wanting to bleach the entire prinit is just to see what happens. I'm experimenting and I've read about whole print bleaching as well as localized bleaching (which I also want to do). I don't have a print that "needs bleaching". I just want to see what the process does to a print. I agree that localized bleaching is going to be more useful than bleaching the entire print. What I do when I run tests like this is cut the print in half, do the experiments on one half and then later tape them back together so I can see the "before and after". I've done this various toners and it makes for a nice reference library of the effects of different processes.

    Anyway, I have now gone back and reread some bleaching articles and realize I've been confused about what the fixer does in the bleaching process. The key to ending the bleaching is to rinse the bleach off. The fixer is what makes the bleaching visible.
     
  8. Dave Krueger

    Dave Krueger Member

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    By the way, Ralph, for Christmas I got a StopClock timer, a Zonemaster meter, and a copy of "Way Beyond Monochrome". I must say that your book is probably the most comprehensive and well detailed treatment of the relationship between light, film, paper, and chemicals ever written. I've been reading it almost daily since I got it. I am particularly appreciative that such a masterful textbook on analog processes was actually produced so deep into the digital revolution when the analog audience is shrinking.
     
  9. Photo Engineer

    Photo Engineer Subscriber

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    Ferricyanide bleach will oxidize the fixer. Eventually, the fixer will be destroyed. Both Hypo and Sulfite are oxidized in this process.

    Ferrocyanide is formed.

    If the right proportions are formed, the print can get a mild blue or brown stain.

    PE
     
  10. Dave Krueger

    Dave Krueger Member

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    Thanks for the scientific perspective, PE. The precision and reliability of your answers is always appreciated.
     
  11. Photo Engineer

    Photo Engineer Subscriber

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    Always happy to help.

    PE