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  1. #21
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    Now all you need is the quantity of each ingredient you need to make the bleach.

    PE

  2. #22

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    PE...Thats where analytical chemistry comes in...e.g. I've been lyophilizing P30 kits which can be quite intructive as to total mass in parts A&B. A little pH manipulation...a little extraction...and of course argentometry and you're almost home.

  3. #23
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    Since Sodium Iodide is not very stable, particularly in solution and KI is not stable for much longer, I would suggest you consider that they are present as Iodates to some extent.

    Also, I have read one report where the catalyst is present in the developer or even coated to give an even distribution when the dye bleach is kicked off. I believe it might be in the developer, but I doubt if it could be reliably coated unless there was a mild ballast of some sort. Of course, then again, many have gotten good results with Dektol, so the reports of it being in the developer may be just reportage or commentary for patent purposes, disclosing other routes to block patents.

    PE

  4. #24

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    Quote Originally Posted by brookse View Post
    OK Folks... Interest is now falling off! I would like first to deal with those who are in the US. Certainly Nicholas, and perhaps akaa. I will PM everyone shortly
    Count me in. :-)

    Thanks
    Matt

  5. #25

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    I'm interested, hell I've been looking for a home bleach for years (but not doing much about it). But

    1) Processing time IS a concern to me, so what are we talking about?
    2) My darkroom has been disassembled so I probably wont be able to mess with it until whenever I get set up again. Dont know when that will be but hopefully this year...but do keep me posted, I'd definitely interested.


    Ilford should be thankful if this can be done, it will increase the paper sales and that's all we need them for. The day I have to make
    my own Ilfochrome paper is the day I give up.

  6. #26
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    I will watch with held breath..............................
    What grain............................................. ...............
    Oh sorry, I forgot you don't shoot Large Format
    Large format Pat.

    http://www.largeformatpat.com

  7. #27
    AgX
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    Quote Originally Posted by brookse View Post
    Quinoxaline 7K is 2,3,6-trimethylquinoxaline...the active dye bleach catalyst. This is the molecule that I now synthesize.

    I remember there was some discussion here at Apug some years ago on details of that catalyst synthesis. But I can't find that thread back.

  8. #28

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    Thanks for the recent posts !

    Wayne: Currently, the process is indeed hybrid, and a bit longer than what you are used to...but this is mainly because I am at the low end of the concentrations of the active ingredients in the bath. Thus, at present, the bleach is more of a dye-bleach bath rather than a silver-dye-bleach bath. So, I have to get rid of a little silver with the equivalent of a blix operation tacked on (this will change). For the moment, I am also sticking with the divided 1st developer approach, which works well in a drum system. Threfore, things are not quite perfect yet for a 3-tank processor.

    I am aware of the APUG posts on hypo modification of standard developers which many of you have used. It would of course be profitable if these experiments were continued.

    Pat: It appears to me that many people in Australia have huge, pent-up frustration concerning Ilfochrome due to lack of availability of chemistry...Can you comment?

    AgX: Keep searching...I could not find anything myself, except for the encouragement of PE.

    I am communicating with a few others via PM. A few issues have cropped up:
    1) Many want a way to successfully use hoarded, outdated material. Although, I too have bought alot
    of the old RC stuff on e-bay for my work, the unknown variables introduced are not conducive to a rigorous approach at present.

    2) For those in other countries, the complex web of international regulation regarding transit is an issue for ME. Having detected that some people are put-off by the prospect of breaking any laws, I have just squeezed my network, and now I can FedX under the umbrella of a biotech company that already has a system for sending molecules worldwide.

    3)Any potential takers need a modicum of standard photo chemicals (especially potassium iodide on e-bay), and initially, need to start off with with the easiest images...flatter, compressed tonal range, without large highlight areas.

  9. #29

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    I'm not sure what you wish to continue in the way of hypo/developers experimentation, seems that has been pretty well explored already. I used home brewed developers including divided developers for years but finally went back to one part because the emulsion changed in the 90s and you could no longer get worthwhile contrast control through varying development. 1/4 teaspoon hypo/liter is what I used, IIRC.

  10. #30
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    Wayne;

    There are several different forms of Sodium Thiosulfate. Which did you use? The pentahydrate? In any case was it the powder form or the pellet form? This makes quite a big difference in the final result.

    PE

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