C41 chemistry help

Hi everyone!
I want to start developing my own film.
after reading a lot of posts here i think i got the grasp of it but still have some questions:
1. Developer:
a. should i use it as one shot? and if yes, do i need to use HAS and DTPA(or other sequesters)?
b. potassium iodide - because i don't think i have a scale accurate enough, can i just make a 0.1% solution and measure in ml?
2. Bleach:
a. i can't find a source for ammonium ferric DTPA or ammonium ferric EDTA. is there any way around? i found EDTA disodium, EDTA tetrasodium, EDTA free acid, iron EDTA, iron DTPA, DTPA 40%. anything i can make with these?
b. i want to make a bleach that will work both on C41 and ECN-2, is it possible?
c. i understand that the bleach can last a long time if i aerate it and replenish the bromide. should i just get a commercial kit for the bleach and just replenish it indefinitely? and if so how exactly?
3. Fixer:
a. can i use the same fixer for C41, ECN-2 and B&W?
b. is there a way to replenish it also?
c. ammonium thiosulfate is quite expensive where i live, should i just get a commercial fixer and replenish it? any recommendations for a brand?

I'll be thankful if anyone answers any of these questions. thanks!

Welcome to Photrio, @photoron!

photoron said:

a. should i use it as one shot?

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You can decide; all variants are being done by home users. Some like to use their developer one shot, some replenish it and some simply reuse it for a couple of times and then discard. What works best for you is mostly a matter of personal preference.

photoron said:

do i need to use HAS and DTPA(or other sequesters)?

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If you mix your own developer from raw chemistry, you may want to add these, especially the HAS (I never use a sequestering agent for DIY developers). If you use a kit (powder or liquid), don't worry about this. The manufacturer has added what's needed.

photoron said:

b. potassium iodide - because i don't think i have a scale accurate enough, can i just make a 0.1% solution and measure in ml?

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Yes. I do not know if a 0.1% solution of KI is stable in the long term, so you may want to make only a small amount and don't use it after a few weeks.

photoron said:

i can't find a source for ammonium ferric DTPA or ammonium ferric EDTA. is there any way around?

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Really, just buy a commercially made C41 bleach. I don't think it's worth the headache of sourcing the appropriate materials to DIY it. Especially because the commercial bleach is super stable and has enormously large capacity, so the expense per roll of film is virtually nil.
You will find a few threads on compounding your own color bleach if you search this forum a bit.

photoron said:

i want to make a bleach that will work both on C41 and ECN-2, is it possible?

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Yes, I always use the same C41 bleach for C41 and ECN2. In principle, any bleach that works with either should work with the other. Simple/old ferricyanide bleaches are still 'allowed' for ECN2 as per Kodak literature, but they're not mentioned for C41, so that combination may not be a good idea. This is not very relevant if you want to use an EDTA/PDTA bleach.

photoron said:

can i use the same fixer for C41, ECN-2 and B&W?

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Yes, absolutely. I always use Fuji C41 (CN16) minilab fixer for everything.

photoron said:

. is there a way to replenish it also?

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Yes. For the commercial product, see the manufacturer's instructions. It helps if you use a couple of washes between bleach and fix to limit carry-over of bleach into fix, which will help the fix to survive longer.

photoron said:

ammonium thiosulfate is quite expensive where i live, should i just get a commercial fixer and replenish it?

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Yes.
Any brand will do. I like Fujifilm because it's easy to get around here and is affordable. Just use whatever is convenient for you.
A color fixer is generally buffered at around pH6.5 or so. B&W fixers are usually acidic. Generally an acidic fixer will also work just fine for C41 or ECN2 film. If you want, you can adjust the pH of an acidic fixer by adding e.g. a hydroxide solution. The pH may not be as stable over time as in a commercial C41 fixer that's buffered at pH 6.5.

You may find these two articles relevant:

photoron said:

Hi everyone!
I want to start developing my own film.

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Welcome to photrio!

So you have not developed C-41 by yourself so far?
Then I highly recommend to make your photography life as easy as possible and buy a C-41 home developing kit from a reputable photo chemistry manufacturer, like ADOX, Fujifilm, Bellini for example.
These kits are extremely easy to use and very cheap. And you'll get perfect results. You will not get better results by mixing your own from scratch, you just have much more work to do.

Film-Niko said:

You will not get better results by mixing your own from scratch

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This is most definitely true. Creating the possibility of mixing color chemistry from scratch at this point is for the most part an insurance against potential future supply problems. In general, using ready-made chemistry is cost-effective, ensures optimal quality and is overall much more convenient than DIY-ing.

photoron said:

2. Bleach:
a. i can't find a source for ammonium ferric DTPA or ammonium ferric EDTA. is there any way around? i found EDTA disodium, EDTA tetrasodium, EDTA free acid, iron EDTA, iron DTPA, DTPA 40%. anything i can make with these?
b. i want to make a bleach that will work both on C41 and ECN-2, is it possible?
c. i understand that the bleach can last a long time if i aerate it and replenish the bromide. should i just get a commercial kit for the bleach and just replenish it indefinitely? and if so how exactly?

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Here are your options for making E-6 bleach from scratch (e.g. Na2-EDTA), which also works for C-41 and ECN-2.

BTW the DTPA 40% would be a good sequestering agent for your color developer.

photoron said:

3. Fixer:
a. is there a way to replenish it also?

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Don't bother replenishing. If you want to save money on fixer, use two bath fixing, which according to Ilford quadruples fixer capacity.

photoron said:

b. ammonium thiosulfate is quite expensive where i live, should i just get a commercial fixer and replenish it? any recommendations for a brand?

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Yes, that's what I do. Fixer and stop bath are the only two soups I do not mix from scratch.

Thanks a lot to everyone for answering!

koraks said:

Really, just buy a commercially made C41 bleach.

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the problem is i have access really just to cinestill powder kit. it will cost me around 45 usd. and most sellers don't ship liquid form kits by air.
i'm trying to find if diy will be cheaper for me.
i don't mind buying one time the kit and keep the blix alive, although i understand that blixes tend to live less than a seperate bleach.

koraks said:

ou may find these two articles relevant:

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I read both, excellent articles! but they mostly cover developers and not bleach.

Film-Niko said:

These kits are extremely easy to use and very cheap.

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see my reply to koraks.

Rudeofus said:

Here are your options for making E-6 bleach from scratch

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Thanks!

Rudeofus said:

use two bath fixing, which according to Ilford quadruples fixer capacity.

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Interesting! do i dilute it as the regular formula 1+4?


more questions :
1. do you know if using the "ammonium UL bleach" from ECN-2 pdf works for C41? because it turns out cheap and doesn't require sourcing ammonium FE EDTA or PDTA.
it uses 1,3-PDTA as sequestering agent.

2. for final rinse, i see several options for fungicides:
a.1,2-Benzisothiazol-3(2H)-one(cas 2634-33-5)
b. katon 886 (cas 55965-84-9)
c. hexamine (cas 100-97-0)
d. or formalin 37%?
what should i use?

3.any one tried making ammonium FE EDTA by this?:
"The Formulary used to sell it, but you can make it from EDTA + 28% Ammonium Hydroxide + FeCl3 (Ferric Chloride). Just mix them in the ratio of 1 Mole, 4 Moles and 1 Mole and add a 10% excess of EDTA."
i think PE posted it once.

Thanks again everyone!

photoron said:

Thanks a lot to everyone for answering!


more questions :
1. do you know if using the "ammonium UL bleach" from ECN-2 pdf works for C41? because it turns out cheap and doesn't require sourcing ammonium FE EDTA or PDTA.
it uses 1,3-PDTA as sequestering agent.

Click to expand...

If it uses PDTA, then it works the same as the official new C-41 bleach, so yes, most likely it will bleach well, and the dyes in your film will remain intact.

photoron said:

2. for final rinse, i see several options for fungicides:
a.1,2-Benzisothiazol-3(2H)-one(cas 2634-33-5)
b. katon 886 (cas 55965-84-9)

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Kodak's final rinse product uses this

photoron said:

c. hexamine (cas 100-97-0)

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Tetenal's STAB uses this. It will hydrolyze into Formaldehyde.

photoron said:

d. or formalin 37%?

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This was PE's suggestion, because it works well (see Tetenal's STAB) and because it is available to amateurs. If you get one of the isothiazols listed above (or Fuji's variant), then these will probably be a lot less smelly than Formaline/Hexamine, and your eyes won't burn while the film dries.

photoron said:

3.any one tried making ammonium FE EDTA by this?:
"The Formulary used to sell it, but you can make it from EDTA + 28% Ammonium Hydroxide + FeCl3 (Ferric Chloride). Just mix them in the ratio of 1 Mole, 4 Moles and 1 Mole and add a 10% excess of EDTA."
i think PE posted it once.

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See the article I linked to, it gives you a working description of this process.

Hi again!
1. Can i use DTPA as pentetic acid instead of DTPA pentasodium salt 40% solution? i know that the acid is acidic, but after ph correction do they act the same?
2. Does anybody have the recipe for flexicolor bleach iii with NTA? i saw many times PE said that the new formula is based on it but never seen any recipe with NTA.
3. any recommendations for replacing ATMP-Na5 in ECN2 developer? and replacing DHPTA in bleach iii?

Rudeofus said:

See the article I linked to, it gives you a working description of this process

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thanks again for all the help

I use the 1 liter UniColor kit for 16 rolls of film following the instructions. I like to do all the processing in two or three days to minimize any color variations.

photoron said:

any recommendations for replacing ATMP-Na5 in ECN2 developer

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Just leave it out. It seems to work fine without it.