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  1. #1

    Join Date
    Aug 2009
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    Potassium Dichromate/Copper sulphate bleach recipes

    Hi all,
    I want to make a bleach to reduce some previously b/w developed and fixed E-4 <sic> film back to a re-developable latent image. (A la kodak tech-pub ae-31, and as in film acceleration)
    Ideally, I'd use C41 or E6 bleach and then develop in RTP C41 dev to avoid emulsion destruction (which can develop until completion, since there's no risk of overdevelopment - all non-image Ag halide is already fixed away).
    Anywho, I've got a C41 kit, but could only afford a litre one, which uses Blix (which is in two separate bottles, bleach and fix to mix?).
    I've also got access to a very small amount of potassium dichromate and some copper sulphate which is otherwise going to be disposed of as well as various acids in the lab.
    Does anybody know a recipe which I can mix up with these and/or limited other ingredients to make a photographic bleach with known properties?
    There's probably about a tablespoon of dichromate, but I only want to use this for a couple of films, which is why I don't want to spend £25 buying ammonium/sodium ferricyanide from Fischer/Merck or a bottle of premade bleach from Moersch with £15 postage.
    Any ideas/recipes would be greatly appreciated.

    EDIT: I realise the chemical dangers - I have a lab with fume cupboards, air filtration, chemical disposal amenities and plenty of protective clothing. I handle potassium cyanide, strong acids (not together!) and cadmium sulphate fairly frequently, so I know what I'm doing with regards to not killing myself, in case any of you were worried.
    Last edited by mattmoy_2000; 10-14-2009 at 08:56 AM. Click to view previous post history. Reason: safety assurance

  2. #2
    Robert Hall's Avatar
    Join Date
    Aug 2004
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    I would check 3 places: Steve Anchel's book, Books from Eddie Ephraums and, of course, Tim Rudman's books on lith and darkroom.

    All must haves for the mix it yourselfers!

    Cheers
    Robert Hall
    www.RobertHall.com
    www.RobertHall.com/mobile
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    Technology is not a panacea. It alone will not move your art forward. Only through developing your own aesthetic - free from the tools that create it - can you find new dimension to your work.



 

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