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Thread: C41 Bleach help

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    Lopaka's Avatar
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    C41 Bleach help

    Well, we just had a discussion about the developer. Now for the bleach.
    The Bleach III 1 gal working solution is discontinued, the substitute for rotary processors is C41SM Bleach in a ready to use tank solution (packaged as two containers totalling 5.4 litres).

    The rotary tube processing instructions list bleach time (with Bleach III) as 6:30. The SM instructions - which are only for SM processors is 1 minute. So how do you use this stuff in the JOBO???

    Bob
    "I always take a camera, That way I never have to say 'Gee, look at that - I wish I had a camera'" -Joe Clark, H.B.S.S.

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    Have you tried it out at 1 minute in the Jobo?, It's not like you can over bleach the film. Extend the time if you are running at a lower temp than the SM does.
    Gary Beasley

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    Use it for the full time of 6:30. This is not a shortie process and cannot tolerate any residual silver metal in the film if you want high quality. The water carryover in a Jobo is much greater than in conventional machines and it dilutes the fix considerably. Besides, extra time won't hurt.

    PE

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    Quote Originally Posted by Photo Engineer View Post
    Use it for the full time of 6:30. This is not a shortie process and cannot tolerate any residual silver metal in the film if you want high quality. The water carryover in a Jobo is much greater than in conventional machines and it dilutes the fix considerably. Besides, extra time won't hurt.

    PE
    Precisely the reason the JOBO instructions call for a rinse between bleach and fix. I just couldn't reconcile in my head 1 min vs 6:30. Thanks for your reply, I'll give it a go.

    Bob
    "I always take a camera, That way I never have to say 'Gee, look at that - I wish I had a camera'" -Joe Clark, H.B.S.S.

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    Lopaka's Avatar
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    Sources

    The 'replacement' bleach for rotary tube processing - SM tank bleach, which comes in a carton of 2 - 2.7 liter bottles ready to use (8824690) is still not being stocked by the usual suspects. Adorama is still attempring to locate some of the discontinued product. The only source I found that stocks this item is Pakor (makers of Pakosol):

    http://www.pakor.com/products/KODAK_...TOKEN=64627647

    Their service is fine, a phone call produces results and same day shipping. But I get nervous when there is only one source - I would like to continue using the Kodak chems but it is getting harder. Does anyone know of any other suppliers that stocks this in US?

    Bob
    "I always take a camera, That way I never have to say 'Gee, look at that - I wish I had a camera'" -Joe Clark, H.B.S.S.

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    Bleach formula for C-41, use 7' at 100 F in a Jobo

    200 ml of 60% Ferric Ammonium EDTA
    10 g/l of Sodium EDTA (Disodium)
    10 g/l of Sodium Sulfite
    20 g/l Ammonium Bromide

    Adjust pH to 6.5 with 28% Acetic acid or ammonium hydroxide (any concentration from 3% to 28% will work but I prefer the 28%) as needed.

    7' 100 F Fix for C-41

    200 ml / L of 60% Ammonium Thiosulfate solution
    10 g/l Sodium Sulfite
    10 g/l Sodium EDTA (Disodium)

    Adjust pH to 6.5 as above.

    Capacity is the same as the Kodak variety, shelf life of this is the same as the Kodak variety. OMG, it is the Kodak variety, that is Bleach I and Fix I the originals, or as close as I can remember.

    All chemicals available from the Formulary.... And NO I don't get a cut or anything. They just happen to carry all of the above.

    Enjoy.

    PE

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    PE...

    You don't add water to make a liter or anything like that to the above recipe???

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    Quote Originally Posted by Photo Engineer View Post
    Bleach formula for C-41, use 7' at 100 F in a Jobo

    200 ml of 60% Ferric Ammonium EDTA
    10 g/l of Sodium EDTA (Disodium)
    10 g/l of Sodium Sulfite
    20 g/l Ammonium Bromide

    Adjust pH to 6.5 with 28% Acetic acid or ammonium hydroxide (any concentration from 3% to 28% will work but I prefer the 28%) as needed.

    PE
    Is this to make one liter of solution? Because at Photo Formulary's prices, it seems awfully expensive (about $32.25 per liter ?? if I'm estimating right) compared to e.g. Adorama's $26.50/gallon of Flexicolor Bleach III (assuming they actually had it in stock). Or does it make a liter of stock solution, which is then diluted to some working strength?

    Also, depending on whether I search PF for "sodium EDTA" or "disodium", I get either "ferric sodium EDTA" or "EDTA disodium salt", respectively, as the result. I assume you mean what they call EDTA disodium salt?

    TIA for the clarification

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    I haven't looked at PE's formula carefully, but I did do some cost comparisons a couple of years ago, and bleaches based on ferric ammonium EDTA just weren't cost-effective to home-brew at the time, at least not given the cost of ferric ammonium EDTA from Photo Formulary, Art Craft, and other suppliers I could find. Presumably Kodak and other manufacturers of photographic bleaches have much cheaper sources of supply.

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    Quote Originally Posted by PVia View Post
    PE...

    You don't add water to make a liter or anything like that to the above recipe???
    That all is in g/l. What else can I say? You can start with 500 ml as the starting volume is irrelevant just so the final volume is not over 1L. You add the ingredients and add water to 1 L. Thats it. I would guess that you have no experience with chemical notation. I suggest Anchell and Troop or Haist for further reading.

    One problem since I posted that set of formulas. You may have sediment. At EK we used all Ammonium salts but they are very hard to get and expensive, so the sodium is used in my post. They may not totally dissolve. Not to worry! Just filter out the sediment. If you can get or make Ammonium EDTA or get Ammonium Sulfite, use that and you will have no sediment.

    Second.....

    Ammonium Ferric EDTA is hard to make and Kodak (K. Steven and J. Surash) own the patent. So, all of the Ammonium Ferric EDTA is made from the EK patent by adding Ammonium Hydroxide to Ferric Oxide and EDTA in a high pressure vessel with cooling. The result is a 60% NH4 Fe EDTA mixture at 60% which is the highest practical concentration available.

    So, when you buy this stuff it is expensive.

    Just remember, when we were developing this formula we had to start with all sodium bleaches, blixes and fixes and then redesign for ammonium equivalents. Our first solutions were hand made in the lab and not too pleasant for all of that.

    I just wish I had a penny for every liter (or gallon) of my blix concentrate sold. If so, I would not be on this forum or teaching workshops. I would own a tropical island somewhere.

    PE

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