potassium ferricyanide bleach

Discussion in 'Color: Film, Paper, and Chemistry' started by ruilourosa, Apr 23, 2003.

  1. ruilourosa

    ruilourosa Member

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    hello, i am using in my home developing a 2% ferri bleach for c-41 processing, am i doing right?, should i add bromide?, i know that if i don´t use the ferric ammonium EDTA bleach the base becomes different, but i don´t mind, í haven´t tried the persulfate-quinone bleach nor the copper sulfate because the ferri one is much more simpler and cheap, plus, i am doing a 6 min bleach temperature between 28-38ºCelcius, is it too much?
     
  2. Ed Sukach

    Ed Sukach Member

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    </span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (ruilourosa @ Apr 23 2003, 10:50 AM)</td></tr><tr><td id='QUOTE'>hello, i am using in my home developing a 2% ferri bleach for c-41 processing, am i doing right?, should i add bromide?, i know that if i don´t use the ferric ammonium EDTA bleach the base becomes different, but i don´t mind, í haven´t tried the persulfate-quinone bleach nor the copper sulfate because the ferri one is much more simpler and cheap, plus, i am doing a 6 min bleach temperature between 28-38ºCelcius, is it too much?</td></tr></table><span class='postcolor'>
    Hello, ruilourosa,

    I've done 400 - ? or so - rolls of C-41 but always using the Bleach-Fix form the Kits; Tetenal, Photocolor, Agfa, etc. This is the first I've heard of Pottasium Ferricyanide applied to color processing.

    Are you mixing your own chemicals? What formulae do you use? What about the fixer? The chemistry in the kits has always been identified as "Ferric-Ammonium EDTA" (or something like that .. I don't have the data sheets handy) ... is something else appropriate?

    I am most interested.
     
  3. mts

    mts Subscriber

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    There is nothing at all wrong with the Pot. Ferricyanide bleach for color work, other than it is environmentally noxious. Formulae for color include more refinements than those for black & white. C-22 was based on the Ferricyanide formula and C-41 replaces it with a more politically correct Fe-EDTA bleach that can be combined with fixer.

    Your results will be improved if you look up and mix the C-22 bleach for use with your C-41 films. Also, note that pH for color processing sets the fixer to about 6.5, and usually includes some Sod. bisulfite to avoid degrading the color dyes.

    M. T. Sandford