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  1. #1

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    C41 Bleach Formula?

    I've started processing c41 at home with Kodak Flexicolor chemicals. So far so good, but it's very expensive. Bleach costs me the most. Does anyone have a good formula for C-41 bleach?

  2. #2
    Photo Engineer's Avatar
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    Yeah, but guess what? Its expensive.

    The Ammonium Ferric EDTA is what is going to cost you the most. You cannot easily get the Ammonium Ferric PDTA that Kodak is using in the newest bleach.

    If someone tries to pass off to you a Ferricyanide bleach, remember that it is cost effective, but you need a wash and clearing bath after the color developer and before that type of bleach or you will cause a lot of stain, and you need to wash well before you go into the fix.

    So, here goes:

    Ammonium Ferric EDTA solution (50 - 60%) 200 ml
    Ammonium Bromide 150 g
    Disodium EDTA 10 g
    Ammonium Sulfite 10 g

    Dissolve in 500 ml water and bring to 1 liter. Adjust pH to 6.5 with 28% acetic acid.

    This is a slower bleach than the new RA Bleach III, so use it for about 6 minutes at 100 F. If you want that faster bleach, then substitute Ferric Ammonium PDTA for the EDTA. PDTA is 1, 3 propylene diamine tetra acetic acid. I have the figures for that as well, but it is hard to get and rather counter productive if you want to save money.

    PE

  3. #3

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    Ammonium Ferric EDTA solution (50 - 60%) 200 ml
    Ammonium Bromide 150 g
    Disodium EDTA 10 g
    Ammonium Sulfite 10 g

    Thanks for the formula! JD Photochem has the Ammonium Ferric EDTA solution (50%) for $19 a liter, Ammonium Bromide for $10 a lbs., Disodium EDTA for $15 a pound, and they don't carry ammonium sulfite. So roughly this mixture is $4 a liter plus shipping. I think that I paid $9/L plus shipping for the Kodak product. Maybe some of the chemicals can be found for less.

    Kodak says to use all the solutions one-shot in a Jobo. Is this really true from the bleach and fixer?

  4. #4

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    Does anybody know offhand if JD Photochem ships to the US? I ask because the usual US photochemistry hobby suppliers (Art Craft, Photographer's Formulary, etc.) either don't carry ammonium bromide or charge much more for it than the $10/pound quoted here -- on the order of $20-$40 for 100 grams (~$90-$180/pound). Alternatively, does anybody have a more reasonably priced US source for ammonium bromide? Also, what about ammonium sulfite? The usual suppliers don't seem to carry that, although some do have ammonium sulfate. (Could that have been a typo, PE?)

    FWIW, I've also recently begun doing my own color processing. So far I've tried one mix-it-yourself blix, which produced overly grainy negatives, and the Paterson Photocolor blix. The latter works much better than the home-mixed blix and is much less expensive than the Kodak chemicals, but given what I've been hearing about blixes, it might not work as well as separate bleach and fix. Still, it might be worth at least trying it if you can't put anything else together. B&H carries the Paterson chemistry.

    If you're interested, here's the site with the home-mixed blix formula I tried, but as I said, I can't really recommend that formula. They've also got a ferricyanide bleach formula (80g potassium ferricyanide and 20g potassium bromide in water to make 1l). I've not tried it, though, in part because from what I understand, potassium ferricyanide is no longer used in commercial bleaches for environmental reasons, and I don't want to bypass environmental concerns. If this information is wrong, though, I might give that formula a try, keeping PE's processing procedure caveats in mind.

  5. #5
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    Quote Originally Posted by Photo Engineer
    Yeah, but guess what? Its expensive.

    The Ammonium Ferric EDTA is what is going to cost you the most. You cannot easily get the Ammonium Ferric PDTA that Kodak is using in the newest bleach.

    If someone tries to pass off to you a Ferricyanide bleach, remember that it is cost effective, but you need a wash and clearing bath after the color developer and before that type of bleach or you will cause a lot of stain, and you need to wash well before you go into the fix.

    So, here goes:

    Ammonium Ferric EDTA solution (50 - 60%) 200 ml
    Ammonium Bromide 150 g
    Disodium EDTA 10 g
    Ammonium Sulfite 10 g

    Dissolve in 500 ml water and bring to 1 liter. Adjust pH to 6.5 with 28% acetic acid.

    This is a slower bleach than the new RA Bleach III, so use it for about 6 minutes at 100 F. If you want that faster bleach, then substitute Ferric Ammonium PDTA for the EDTA. PDTA is 1, 3 propylene diamine tetra acetic acid. I have the figures for that as well, but it is hard to get and rather counter productive if you want to save money.

    PE
    garbage

  6. #6
    OldBikerPete's Avatar
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    Quote Originally Posted by OldBikerPete
    garbage
    Sorry, sorry - I didn't mean that your post was garbage, I was trying to post a response and I was getting a web page error. In the process of poking around trying to get something to work, guess what?:o

  7. #7
    OldBikerPete's Avatar
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    Quote Originally Posted by Photo Engineer

    Ammonium Ferric EDTA solution (50 - 60%) 200 ml
    Ammonium Bromide 150 g
    Disodium EDTA 10 g
    Ammonium Sulfite 10 g

    Dissolve in 500 ml water and bring to 1 liter. Adjust pH to 6.5 with 28% acetic acid.

    PE
    This is the response I was trying to make when I posted "garbage".
    How important is the Ammonium component of this recipe?

    I mean if one were to replace NH4Br with KBr or NaBr and (NH4)2.SO3 with Na2SO3 or K2SO3 and adjust the quantities to maintain the same concentrations of Br and SO3 in solution, what would be the effect/s other than a tendency to buffer at different pH before correction with acetic acid (or -say- Na2CO3)?

  8. #8
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    You can replace the ammonium sulfite with an equal weight of sodium sulfite, but you cannot replace the ammonium bromide with sodium bromide or it will be VERY slow to bleach. For the purists the ratio of the molecular weights of ammonium to sodium are virtually unimportant for these purposes.

    You can use EDTA acid and neutralize it with ammonia as well rather than use disodium EDTA. There are many ways to do this.

    All bleaching in this is based on a mutual reaction of ammonium ion, bromide ion and ferric EDTA (or PDTA). If you put in too much sodium ion, the bleach slows down to a crawl. Keep the sodium ion at a minimum and if you overshoot in pH adjust, going too acid, don't use sodium hydroxide, use ammonium hydroxide to go back up in pH.

    You can get ammonium sulfite from the Formulary by special order (I think) or from ANTEC (kyantec.com).

    Avoid all potassium ions like the plague in both the bleach and fix.

    Film blixes have a great tendancy to cause silver retention with associated higher grain and blocked highlights in the print. They are often less stable than bleach then fix processes. There are blix formulas. I am working on one right now that should solve these problems.

    PE

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    JD will ship any place. Certainly to the US. Notice the prices are in US $.

    But to save money on bleach and fix you might want to consider buying bigger bottles. The bigger the bottle the less per litre. Plus aren't you supposed to mix oxygen into the bleach?

    I replenish bleach and fix.

  10. #10

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    Quote Originally Posted by Nick Zentena
    JD will ship any place. Certainly to the US. Notice the prices are in US $.

    But to save money on bleach and fix you might want to consider buying bigger bottles. The bigger the bottle the less per litre. Plus aren't you supposed to mix oxygen into the bleach?

    I replenish bleach and fix.
    Hi Nick. Do you use a Jobo? If so, what chemistry do you use?

    I don't really understand why Kodak recommends using the bleach only once in a Jobo, since bleach actually needs lots of oxygen to work properly. (I can see why the increased oxygenation (right word? I'm not a chemist) can cause problems for developer and to a lesser extent to fixer, but bleach?) I'm thinking of using the replenishment scheme that Kodak recommends for non-rotary systems. That would quadruple, or so, the amount of use that I'd get out of the bleach.

    What about fixer? Can I use it until Edwal Hypo Check says otherwise?

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