Guidance on "C-41" base not clearing - first attempt at homebrew

GBS · Sep 13, 2021

Mr. Memphis. I like that. I was in Egypt twice, many years ago. Very good memories there. Not far north from me is another town, Cairo. In the state of Illinois. This is not coincidence.

Thank you for the Zone V C-41 formula. I will try that one day.

I'm nearly certain I was using a Sodium Sulfite & Acetic Acid stop bath before the bleach, and a Sodium Sulfite clearing bath after the bleach. I use both of those with my ECN-2, so I don't see why I would have skipped them. But--many of these tests were over a year ago, so I may have missed the clearing baths.

Either way, only when I moved to RA bleach did mt tests come out correctly.

It's possible the difference in C-41 and ECN-2 Ferricyanide formulas was enough to cause the difference. I don't know.

Developer preference aside, C27, C29, and C42 do not work with the ECN-2 Ferricyanide bleach formula. They do work well with RA bleach. I just want to be clear in case anyone else stumbles on this problem someday.

Rudeofus · Sep 13, 2021

I don't think, that there is anything special about the ECN-2 bleach formula, except that it is more powerful than C-41 bleach and can therefore hurt stabilizers. if bleach leaves too high stain, then either there was color developer left in the emulsion, which was then oxidized by the bleach and created stain, or the bleach left metallic silver behind. These two cases can be easily separated with an IR capable film scanner.

mohmad khatab · Sep 13, 2021

Rudeofus said:
I don't think, that there is anything special about the ECN-2 bleach formula, except that it is more powerful than C-41 bleach and can therefore hurt stabilizers. if bleach leaves too high stain, then either there was color developer left in the emulsion, which was then oxidized by the bleach and created stain, or the bleach left metallic silver behind. These two cases can be easily separated with an IR capable film scanner.

These are very clever and very accurate notes from Alexander's father (Respected), God bless him.

mohmad khatab · Sep 13, 2021

GBS said:
Mr. Memphis. I like that. I was in Egypt twice, many years ago. Very good memories there. Not far north from me is another town, Cairo. In the state of Illinois. This is not coincidence.

Thank you for the Zone V C-41 formula. I will try that one day.

I'm nearly certain I was using a Sodium Sulfite & Acetic Acid stop bath before the bleach, and a Sodium Sulfite clearing bath after the bleach. I use both of those with my ECN-2, so I don't see why I would have skipped them. But--many of these tests were over a year ago, so I may have missed the clearing baths.

Either way, only when I moved to RA bleach did mt tests come out correctly.

It's possible the difference in C-41 and ECN-2 Ferricyanide formulas was enough to cause the difference. I don't know.

Developer preference aside, C27, C29, and C42 do not work with the ECN-2 Ferricyanide bleach formula. They do work well with RA bleach. I just want to be clear in case anyone else stumbles on this problem someday.

You are welcome my dear at any time, I live literally next to the Pyramids, I can see it from the window on the eighth floor.

This is the origin of the word Memphis

Trust me, (C27 - 29) is an ominous developer.
Even if all the experts of the earth agreed that it was the best, I would never use it again, it was absolutely ominous.
Regardless of the formula of the bleaching lotion, the infamy comes from this ominous developer, I hate it,
Trust me, even if you brought him a bleach solution from Mars, it wouldn't work very well.
There is something mysterious about this developer, something that is outside science and logic. There is something within (metaphysics) in this developer,
I moved away from him and the world finally smiled at me and noticed the big difference in the freshness and brightness of the image. After I used that primitive formula Zone V C-41 .

Trust me, I won't deceive you.. I have no interest in deceiving you.
Do not look to the past and do not try to find out the reason, because in the end you will not get a logical and convincing reason for the occurrence of these problems.
As I told you, this is a resentful developer and the laws of chemistry that we know do not apply to him. He works according to (metaphysical) science, so I sincerely advise you to get rid of him completely and turn that page of your life so as not to waste your time.
Then you should go for that primal formula I sent you with copper bleach (make sure to use distilled or deionized water).
Then you will find that the world smiled at you.
You'll come and tell me that, I know.

GBS · Sep 13, 2021

Rudeofus said:
These two cases can be easily separated with an IR capable film scanner.

. I don't have one of those at the moment, but when I get the chance, I will reach out to you and see if you can explain more. Right now, the base is clearing correctly with RA bleach. I am okay with that.

mohmad khatab said:
Then you should go for that primal formula I sent you with copper bleach (make sure to use distilled or deionized water).

I'm all set up with my RA bleach for C-41 and Potassium Ferricyanide bleach for ECN-2. If I try Zone V, can I use one of those? I am not trying to mix yet another bleach.

Rudeofus · Sep 14, 2021

GBS said:
. I don't have one of those at the moment, but when I get the chance, I will reach out to you and see if you can explain more. Right now, the base is clearing correctly with RA bleach. I am okay with that.

Did you try rebleaching these dark strips with RA bleach? If that works, then the Ferricyanide bleach didn't bleach. If that made no difference, then we know, that the black comes from dyes, which means, that color developer was somehow carried over into the bleach step.

GBS said:
I'm all set up with my RA bleach for C-41 and Potassium Ferricyanide bleach for ECN-2. If I try Zone V, can I use one of those? I am not trying to mix yet another bleach.

RA bleach for C-41 is clearly the best, if you have access to this stuff for an acceptable price. There is no point in messing with other bleaches as long as that is the case.

mohmad khatab · Sep 14, 2021

GBS said:
. I don't have one of those at the moment, but when I get the chance, I will reach out to you and see if you can explain more. Right now, the base is clearing correctly with RA bleach. I am okay with that.

I'm all set up with my RA bleach for C-41 and Potassium Ferricyanide bleach for ECN-2. If I try Zone V, can I use one of those? I am not trying to mix yet another bleach.

Yes my dear ,,
Trust me, Mr : Zone V's recipe can work with any type of bleach with great success.
- But I use copper bleach with this formula to complete the low-cost system.
- The dining table for the poor (containing cheap popular foods) - If it includes a plate of caviar, this will be absolutely illogical, caviar needs to be present in other circumstances, on another table and next to other foods.
- This is my personal view.
It is true that there is no health objection that prevents eating caviar next to or with eating (cheap popular foods), in any case you will feel full. But you will definitely feel uncomfortable.

- I fully agree with the theory of eng / Elon Musk to the fullest extent, (reaching the desired goal in the cheapest and safest way).
Traditional copper bleach is the cheapest and most successful, proven option.
In terms of re-bleaching, copper bleach is the best option, and this is from personal experience.

GBS · Sep 15, 2021

Rudeofus said:
Did you try rebleaching these dark strips with RA bleach? If that works, then the Ferricyanide bleach didn't bleach. If that made no difference, then we know, that the black comes from dyes, which means, that color developer was somehow carried over into the bleach step.

I did try to re-bleach with RA. It's hard to imagine developer being carried over. I used a stop bath with 10g Sodium Sulfite and a rinse after the stop, before the bleach. I don't doubt your experience, just hard to believe There was enough to stain the entire strip so dark. I have RA bleach now, so I'm sticking with that for C-41. Is it true it can last "forever" with oxidation?

mohmad khatab said:
Traditional copper bleach is the cheapest and most successful, proven option.

What is your bleach formula?

Rudeofus · Sep 16, 2021

GBS said:
I did try to re-bleach with RA. It's hard to imagine developer being carried over. I used a stop bath with 10g Sodium Sulfite and a rinse after the stop, before the bleach. I don't doubt your experience, just hard to believe There was enough to stain the entire strip so dark. I have RA bleach now, so I'm sticking with that for C-41. Is it true it can last "forever" with oxidation?

Yes, it is hard to believe, but the stain has to come from somewhere. It would be interesting, if you could take a small snipped of unprocessed film (e.g. the film leader), and run it through clearing bath, ECN-2 bleach and the remaining process chain. If you get stained film, then ECN-2 did all the bad stuff by itself.

One more thing: you write, that your clearing bath only includes Sodium Sulfite. If Sodium Sulfite is freshly mixed into water, its pH can be quite high. Is there a chance, that your clearing bath did cause the stain? Ron Mowrey recommended a mixture of Sodium Sulfite/Metabisulfite and Acetic Acid, pretty much what Mohmad uses.

Since you now have a viable bleach, which will last you for a long time, I understand, if you don't feel too experimental, but if you ever return to ferricyanide bleach, you should perform a few tests before you run another roll.

GBS · Sep 19, 2021

These are all great suggestions, thank you! I would like to come back to this and figure it out. I read somewhere else on here that Sod Sulfite alone is okay for the post-bleach clearing bath. This is what I use for the ECN-2 process with no issues. Should I have acetic in this step as well?

Before the bleach, for C-41, I had Sod Sulfite mixed with my stop, which was acetic acid (vinegar at 5% I think). So I think that's correct?

I will follow your suggestions. I will take unexposed C-41 film and run it through the chain (minus developer). Depending on that result, I will also try a small batch of C-41-specific ferricyanide bleach in the chain.

Thanks a ton

AndrewBurns · Sep 28, 2021

My experience with ferricyanide bleach is that you really need good washing between dev/bleach and bleach/fix. So I'd recommend an acetic acid stop after dev followed by 3 x washes, then bleach, 3 x washes, then fix. I've seen when processing in a hand-tank it takes about 3 x washes before I can't see any more yellow from the bleach coming out of the tank, and I've had good results doing this.

GBS · Sep 29, 2021

Thnk you! Have you used ferricyanide bleach with C-29 or C-42? If so, did you mix the ECN-2 formula, or a different one? I was trying the ECN-2 bleach formula with C-29 and C-42 and couldn't get it to work. I was doing Aceitc stop with Sodium sulfite with at least 3 washes before and after bleach and still had a consistently dark base stain. RA cleared it up. Will test a different ferricyanide formula down the line and report back

AndrewBurns · Sep 29, 2021

No sorry I've only used ferricyanide bleach with ECN2 film, I've only processed C41 using Kodak bleach III and I've never had any issues going straight from dev to bleach in that case.

GBS · Sep 29, 2021

Ah cheers, thanks. that makes sense. ENC-2 is working fine for me, but c-29 and c-42 don't work with that bleach.

Guidance on "C-41" base not clearing - first attempt at homebrew

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