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  1. #1

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    Hydrogen peroxide and a RA4 roller transport system

    I am always on the lookout for new tools to add to my tool box for C41 and RA4 processing. I currently use a Fujimoto CP51 to do my RA4 printing, and I am interested in trying to figure out a way to apply hydrogen peroxide to a roller transport system. The CP51 uses a 6L tank for both the bleach fix and developer. I use Kodak RA developer RT with the additive to reduce oxidation for even lower utilization. I do monitor my chemistry with Kodak control strips and plot the results.

    From current threads I have found that people have used 3% hydrogen peroxide at a rate of 10ml/L to 20ml/L of RA4 developer. I believe that I also read after an hour the effects of hydrogen peroxide cease to work. If this is true does the developer chemistry return back to its initial state prior to adding the hydrogen peroxide?

    This short life span of hydrogen peroxide would be ideal for a roller transport system. I could add it, and then use it and after a hour I would be back to regular processing.

    Any comments would be welcome.
    Last edited by stevewillard; 12-10-2009 at 03:22 AM. Click to view previous post history.

  2. #2

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    Why do you want to use hydrogen peroxide?

  3. #3

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    Isn't it H2O2 that has an extra oxygen attached to H2O (water)? If so it will release the extra O(xygen) and cause your developer to oxidize more rapidly? It may be for the Bleach and not for others?

  4. #4
    Dave Pritchard's Avatar
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    Hydrogen peroxide is bleach. (Not chlorine bleach, but bleach). Put some on your hair to test this. Ever hear of a peroxide blond?

  5. #5
    tiberiustibz's Avatar
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    I think it's to adjust contrast. And i think it destroys the developer too.

  6. #6
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    Hydrogen Peroxide will increase contrast if added to a color developer. Speeds also shift so that the print must be rebalanced.

    The Hydrogen Peroxide will rapdily decompose in your developer and lead to a pretty inactive developer in about 1 hour. There are patents on this by Kodak, Agfa, Konica and Fuji as well as patents on the use of Cobalt Hexammine Chloride which is slightly more stable but releases Ammonia in the developer causing fogging.

    This is called RedOx Amplification.

    It can also be used to cut the silver level during coating to obtain the normal contrast, thereby saving in coated silver in color print materials.

    PE

  7. #7

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    Thanks PE. My hope was that the hydrogen peroxide would just disappear in about an hour and not be harmful to the developer. I guess that is not the case. Oh well...

  8. #8
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    If you add enough H2O2 to do the job, the developer is a one-shot!

    PE



 

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