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  1. #51
    Photo Engineer's Avatar
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    I have been studying the washless process.

    Regarding retained silver levels, it is the silver metal specks that remain un-bleached that cause problems with image quality (grain, sharpness and color). Used properly, there should be none of these specks in a washless process, just some traces of silver halide complexes. The silver halide complexes retained in a washless process cause a different problem. They can affect image stability. I have no information on this whatsoever, but having examined the chemical changes in the bleach and fix, I see what they have done, and it follows from R&D I am familiar with and have been working on myself here. It can work. It apparently does. I have gotten good results from it. In fact, Super Universal Fix VIII uses similar chemistry based on my R&D at Kodak.

    SUF VIII uses a method of swelling gelatin which facilitates removal of silver halide complexes from the coating and allows reduced wash times. It also forms a different type of complex.

    PE

  2. #52

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    Quote Originally Posted by Photo Engineer View Post
    I am not aware that RA-4 processes are washless. I'll have to check.

    I do know that C-41 can be washless but only using the C-41 Flexicolor RA Bleach and Fix. They have been modified to prevent problems with any possible retained silver complexes. In addition, the Final Rinse RA III must be used with this washless process.

    If you don't use the proper chemistry, you can end up with unstable negatives.

    You can use the RA chemistry with a wash however, with no problems.

    PE
    The fuji CN-16 process is wash less as well. Dev, bleach, fix1, fix 2(overflows to fix 1) then four seperatly replenished STAB tanks.

    On the frontiers the final rinse is Deionized water with a tablet added to the tank....don't remember what was in the tablet but it sure smelled like chlorine.

  3. #53
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    Quote Originally Posted by Photo Engineer View Post
    Yes, you can make a film blix!

    Now, let me explain the consequences and the reasons behind the problems.

    1. Ammonium Ferric EDTA only comes as a liquid of about 40% concentration or about 400 g/l.

    2. Ammonium Thiosulfate only comes as a liquid of about 60% concentration or about 600 g/l.

    3. Sodium salts of the above are less soluble and come as powders. They are far less active than the ammonium salts.


    Now, let us look at the E6 bleach and fix concentrates. The bleach itself consists of 2 bottles that total to approximately 3 Liters all on their own. The fixer consists of one bottle of 423 ml. Each of these makes up 1 gallon or 3.8 L of solution.

    If you mixed each one up and then mixed them together to make a blix, the resultant mixture would be 50% more dilute than the original leading to less activity.

    If you mix them together in 1 gallon (3.8 L) then they have the same working strength as desired in separate bleach and fix, but the oxidation and reduction power of the two main ingredients conflict and the solution becomes short lived (less than a month, perhaps less than a week).

    Either of these would make a suitable blix given enough treatment time, but the first, if it worked, would be slow, and both methods would yield a very unstable blix. The second would be fast but very expensive.

    Lets now look at C-41. Bleach III is at working strength as-is, so that adding hypo solution only dilutes it further and weakens it. The same arguments hold as above regarding stability. The blix would decompose rather quickly. So, you cannot make a good blix from C-41 chemistry as it exists. You need to reformulate and can’t use Bleach III.

    Powder kits made with sodium salts of the ingredients is possible, but these become very slow acting. Remember that sodium based fix solutions are not “rapid fix” solutions. You have to go to ammonium based fix solutions to have a rapid fix!

    So, here is a quick rundown of the above:

    Use solid powders and the blix is too slow.

    Mix the bleach and fix parts normally then mix together, and the kit becomes weaker and less stable due to dilution. It also requires more time due to the loss in strength and you end up right back where you were with a bleach and fix situation. Mix the two parts without dilution if possible and the blix is fine for rate but much less stable. It becomes a one-shot essentially.

    In the end, you have about equal costs or more with a blix due to the shorter shelf life after mixing and the lower capacity.

    With a bleach-fix, the process is a tad more complex but not necessarily longer.

    With a blix, there is a chance to have silver retention with some film / blix combinations. This is due to the heavy silver load, the type of silver developed, and certain inhibitors used in color films to control image quality. The dyes also act to protect the silver from the bleach and so the dye cloud must be rendered penetrable by the blix.



    There are ways to limit any problems with blix kits.

    Use a long blix time! Use 2x – 4x the suggested time or more. It will not hurt. It does make the process longer.

    Mix the two parts right before use and in the quantity you are going to use. Don’t re-use it. But, this increases cost.


    There is a summary of some of my work over a 30+ year period on bleaches and fixes. The Bleaches and Blixes included Copper, Cobalt, Iron and various organic oxidants in order to optimize Blixes for films.

    As Ray said above, the problems with Blixes used with films were known years ago.

    Best wishes to you all, and whatever you choose, may it work well for you.

    PE

    YES. Thank you so much for your help. This is exactly what I was lookin for.

  4. #54

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    Quote Originally Posted by Photo Engineer View Post
    I can tell you how to make your own RA-4 Blix and your own C-41 bleach and fix. That is about it.

    PE
    Can you help us out here. I would like to make my own if it is a reasonably safe process and can be done with our normal weigh scales.

  5. #55
    RPC
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    You might try a search on this site, or go through the archives. In going through the color archives in the past I have seen many bleach-fix, bleach, and fixer formulas from PE and others, often with useful information about their workings.

  6. #56
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    Quote Originally Posted by Kilgallb View Post
    Can you help us out here. I would like to make my own if it is a reasonably safe process and can be done with our normal weigh scales.
    What do you want? This is a broad question.

    RA4 blix:

    100 ml NH4 Fe EDTA solution (standard in the industry)
    100 ml NH4 Thiosulfate solution (another industry standard
    10 g Na2 EDTA
    10 g NH4 Sulfite

    All in 1 L of water with pH to 6.5 with either acetic acid or ammonium hydroxide.

    This should do.

    PE

  7. #57
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    As long as this subject has resurfaced I am still looking for a good c-41 kit that uses bleach and fix separately. I was able to pick one up from Catlabs a while back but this one is no longer available.

    A Kodak Flexcolor kit seems available, but it appears only to be designed for the mini-lab systems and there is no direction on how to use it with a Jobo, if it can at all.

    If anyone has any guidance on this I would appreciate it, otherwise I am back to the Tetanal or Rollei kits.
    Dan

    The simplest tools can be the hardest to master.

  8. #58
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    I can't point you to a source for a separate bleach&fix kit, but you may want to have a look at my recent article for converting BLIX kits into separate bleach&fix setup. No special tools are required, and all the necessary chemistry can be easily sourced from Formulary, Suvatlar and other sources.
    Trying to be the best of whatever I am, even if what I am is no good.

  9. #59
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    Quote Originally Posted by Pioneer View Post
    As long as this subject has resurfaced I am still looking for a good c-41 kit that uses bleach and fix separately. I was able to pick one up from Catlabs a while back but this one is no longer available.

    A Kodak Flexcolor kit seems available, but it appears only to be designed for the mini-lab systems and there is no direction on how to use it with a Jobo, if it can at all.

    If anyone has any guidance on this I would appreciate it, otherwise I am back to the Tetanal or Rollei kits.
    The bleach and fix set here can be used with a Jobo.

    PE

  10. #60
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    That is an exceptionally good review Rudeofus. I'll put together an order to the Formulary and prepare to try this out. Thanks a lot.

    A note of clarification though. In your article you indicate that both Rollei and Digibase kits are already separate bleach and fixer kits but from what I can tell online the current Rollei offering is a Blix kit.
    Dan

    The simplest tools can be the hardest to master.



 

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