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

[koraks]

This wasn't a ferricyanide bleach, or was it? If it was, you might try soaking those strips in a carbonate solution (let's say 1%; it's not critical) and see if there's any change.

 

[Rudeofus]

To be honest, I am surprised at the pH 10.6 you measured with your freshly mixed C-27. When the chemicals are right and my pH meter is properly calibrated, the pH I get is right at 10.16. Something strange is going on. Did you substitute any chemicals?

 

[Donald Qualls]

Looks like magenta-forming layer may have some fog.

I've read about a magenta cast due to active developer getting into the (alkaline) fixer with C-41 -- this was originally attributed to use of ferricyanide based bleach on Fuji materials, but later found to be not brand specific. Thiosulfate is a mild fogging agent, so if there's active developer in the fix, you can get some development of fogged halide before the fixer can dissolve it, leading to yellow and magenta layers (the top ones) showing most -- but since magenta dyes are stronger than yellow,and there usually won't be much of this because C-41 fixers are so fast, what you see is a magenta cast on the negative. The slower your fixer, the more this effect will be visible if it occurs.

Fixes for this are to ensure that all developer is washed out of the film before it gets to fixer (add a short wash step between dev and bleach and between bleach and fix), and/or to use a faster fixer (add some thiocyanate to the thiosulfate based rapid fixer). Another possible option is to use acidic fixer (to prevent developer carry-over from being active), but C-41 is designed to have mildly alkaline fixer.

 

[Rudeofus]

How would color developer get into fixer? There is at least a bleach and a wash step between these two.

 

[Donald Qualls]

How would color developer get into fixer? There is at least a bleach and a wash step between these two.

Not sure, just reporting what I've read and understand for the mechanism.

 

[GBS]

As always, thanks a ton for the guidance. My learning curve is flattening, but this one is tough.

@koraks Could you be more specific? I have Sodium Carbonate. What would be the weight to add to 250 or 500mL water?

@Rudeofus I agree; this is really strange. I did not substitute any chemicals, and triple-checked this time. Same results as last time, so I'm beginning to suspect something I have is off/wrong. Here are photos of exactly what I used. (I'm not sure how it happened, but I see I am 0.3g/L short on CD-4. Obviously that needs correcting, but will that alone result in the major shift?)

The following chemicals pictured above were also used in my ECN-2 batch with no problems:
Sodium Sulfite
Potassium Carbonate
Potassium Bromide
Sodium Bicarbonate (baking soda)

If a chemical is wrong, it would lead me to believe it's one of the ones I did not use in ECN-2:
Hydroxylamine Sulfate
Potassium Iodide
CD-4

@Donald Qualls I know Ferricyanide Bleach has its down sides, but I added 10g/L Sodium Sulfite in the stop. Then, after bleach, I wash, then wash in a Sodium Sulfite clearing barth, and wash again before fix.

 

[mshchem]

Kodak 25L C-41 Flexicolor Fixer and Replenisher for Color Negative Film
Kodak
Product #:
EKY6600027

Manufacturer #:
6600027

UPC:
086806600026

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[GBS]

Kodak 25L C-41 Flexicolor Fixer and Replenisher for Color Negative Film
Kodak
Product #:
EKY6600027

Manufacturer #:
6600027

UPC:
086806600026

• Email a friend
• Save

• 

Be the first to write a review

- Kodak Fixer and replenisher
- For Color Negative Film




Our Price: $11.50
Earn 115 U-REWARDS Loyalty Points

• QTY

In Stock

Pickup now at Fairfield, NJ

Hi @mshchem - As I mentioned, I am already using C41 fixer my local lab gave me. I should've been more clear. I am already using Flexicolor Fixer.

 

[Donald Qualls]

I don't think the magenta issue is actually specific to ferricyanide bleach -- I got the impression, from what I read, that even with EDTA or PDTA bleaches you could still get it if any development takes place in the fixer. Could even happen due to carried over developing agent from a previous run with less washing, if I've understood what's happening correctly.

Using real C-41 fixer won't help if a chemical carry-over is causing your color cast, but it might help narrow down the problem. At that price, it's tempting to suggest we should all use C-41 fixer for both color and B&W. That'll actually be a one or two jugs of concentrate, totaling 6.25 L for dilution 1+3 to make 25L of working solution, BTW -- you don't have to ship 25+ kg of water solution to wherever you are that's not New Jersey...

 

[GBS]

I don't think the magenta issue is actually specific to ferricyanide bleach -- I got the impression, from what I read, that even with EDTA or PDTA bleaches you could still get it if any development takes place in the fixer. Could even happen due to carried over developing agent from a previous run with less washing, if I've understood what's happening correctly.

Using real C-41 fixer won't help if a chemical carry-over is causing your color cast, but it might help narrow down the problem.

Thanks, @Donald Qualls. My fix is clearing test clips and ECN-2 fine.

 

[mshchem]

I don't think the magenta issue is actually specific to ferricyanide bleach -- I got the impression, from what I read, that even with EDTA or PDTA bleaches you could still get it if any development takes place in the fixer. Could even happen due to carried over developing agent from a previous run with less washing, if I've understood what's happening correctly.

Using real C-41 fixer won't help if a chemical carry-over is causing your color cast, but it might help narrow down the problem. At that price, it's tempting to suggest we should all use C-41 fixer for both color and B&W. That'll actually be a one or two jugs of concentrate, totaling 6.25 L for dilution 1+3 to make 25L of working solution, BTW -- you don't have to ship 25+ kg of water solution to wherever you are that's not New Jersey...

Unique photo uses UPS their ground shipping to me here in Iowa is very reasonable. I still use Kodak rapid fix with hardener for all b&w. For C-41 and E6 Fuji sells a Universal fixer 50 bucks to make 25 gallons, it's a huge 5 gallon cube, enough to last two lifetimes, I got one by accident, Unique had free shipping on everything at the beginning of the Covid shutdown. I went all in for TEOTWAWKI. I have enough color chemistry now I could develop 10,000 rolls of Ektachrome.
Unique is great in that they will sell you individual bottles of chemistry, especially C-41. Like the OP I would just pick up Flexicolor from my local lab. They are gone now.
SORRY FOR BREAKING IN TO THE HOME BREW DISCUSSION.

 

[Anon Ymous]

@GBS CD4 is an acidic salt, so using less would result in higher pH. Wether or not this is enough to cause such a pH discrepancy I cannot tell.

 

[koraks]

@koraks Could you be more specific? I have Sodium Carbonate. What would be the weight to add to 250 or 500mL water?

Something like 2.5g for 250ml. It's not critical at all. A teaspoon will do. It only makes sense though if you used a ferricyanide bleach and for some reason followed it with an acidic bath with no rinse in between.
If it was a ferri bleach and there was no wash between develop and bleach you're basically screwed.
If it was a proper c41 bleach (not ferri), ignore my suggestion altogether; it only makes sort of sense for a ferri bleach that somehow resulted in the formation of prussian blue on your film.

 

[Rudeofus]

I am still confused by your pH measurements. You mixed C-27 on Sept 7 and got a pH of 9.6, which you then adjusted to target pH. Today you mixed C-27 again and got pH 10.6 out of the box. Something is off here ....

 

[GBS]

@koraks Thanks. Yes, ferri bleach, but I've been pretty thorough with the washing--and ECN-2 has held up fine through the same process (with different developer). I'll try the carbonate wash and see what happens.

My steps are: Develop > Stop (with Sodium Sulfite) > Wash > Bleach > Wash > Sodium Sulfite Clearing Bath > Wash > Fix > Wash > Final Rinse.

I am still confused by your pH measurements. You mixed C-27 on Sept 7 and got a pH of 9.6, which you then adjusted to target pH. Today you mixed C-27 again and got pH 10.6 out of the box. Something is off here ....

@Rudeofus Sorry for the confusion. Please bear in mind, I originally said, on September 7, that the low reading was with a cheap, uncalibrated meter--and the pH reading at that time was similar to my ECN-2 formula which was developing nicely. I did not adjust C27 at that time because I did not trust the meter. I said

...I'm going to mix the buffers and calibrate it before I make any decisions based on what it's reading.

. When I tried to calibrate, it only worked for one day. I've since bought another meter, slightly better quality, and started over. The original 9.6 should be disregarded in factoring in the error.

I agree something is off. I see where I am 0.3g/L short on CD-4. Could that have caused such a major shift? I also attached a photo of the chemicals I used and the formula. 4 of the 7 chemicals are also used in ECN-2, which is working well. That leaves the other 3, unless I'm missing something.

 

[koraks]

That's a pretty thorough wash/rinse cycle; I don't expect the carbonate bath is going to do much.

You're 0.3g short in cd4? On what volume? Yes, that might make a difference in pH. Obviously the weight measurements should be reasonable accurate when mixing this stuff.

 

[Rudeofus]

@GBS: did you do the plausibility check for your pH meter with 5 g/l Borax in water? Does your pH meter show something around 9.23 ?

 

[GBS]

@koraks Thanks for following up. I was 0.3g/L short. I know that will have an effect on pH and development, but it seems like that's a compound error, as it shouldn't cause the massive shift and extra dark base. I am trying to avoid a 3rd test batch to preserve my CD-4, but if 0.3g/L could make that difference, I'm happy to try again.

@Rudeofus Thanks for asking. I appreciate your continued effort. I don't have Borax and it was out at the store last 2 times I visited. I will be checking again later today. In the meantime: I did receive 3 buffer packets for calibrating my pH meter. I used those to calibrate the meter and believe the meter is relatively correct now. My ECN-2 formula reads correctly (10.25) and that development works well. I agree that something is off, but other than the 0.3g/L I was short on CD-4 by accident, I cannot figure out what it is. (I know the CD-4 error will cause inaccurate results, but the excessively dark base in two batches seems extreme to me and like something else is going on)

 

[Rudeofus]

Please confirm: you were 0.3 g/l CD-4 short, but you did adjust pH to correct value at 10.16. Yes?

 

[GBS]

Thanks for asking. Both attempts, same results. Here’s what I can recall.

1st attempt, no valid pH reading, no adjustment (do not recall CD-4 measurement)

2nd attempt, mistakenly 0.3g/L short CD-4, adjusted to 10.16.

What color is CD-4? Mine is a grey/beige. I’m attaching photos. The one in the jar most closely resembles what it looks like to my eye under those lighting conditions.

 

[GBS]

Hey everyone! I hope you're all hanging in there and enjoying the extra daylight (in the Northern Hemisphere, at least).

I'm pulling my hair out with this.

It's been a couple months since my last attempt. I noticed 2 small weight errors last time, and was hopeful that was the problem. No luck.

Round 3 on left (fresh Gold 200), lab on right (for example):


I was so sure I had it right this time, I neglected to check the pH in advance, only after the problem persisted. pH is 10.44. What is going wrong?

Again, for reference, some of these same chemicals are working fine in my ECN-2 development, so I feel I can rule those out.

These are the chemicals in C-29 that are not being used in ECN-2:
Hydroxylamine Sulfate
CD-4
Potassium Carbonate
Potassium Bromide

I'm using C-29 from here, with 1.5 KBr as recommended here

Screengrab from my working printout (in mixing order), which omits A905 and Calgon


I got a small sample of CD-4 from Artcraft I can try next time, but he said he hadn't gotten any complaints so it seems unlikely that's it.

I believe I've followed all the great suggestions I've gotten so far, and am still getting this consistently dark base. It's driving me nuts. I'm not a chemist by any stretch, but I'm usually pretty good at problem solving.

Any more thoughts are very welcome. Thanks a ton.

 

[GBS]

If anyone comes across this thread, I'm back with the solution.

As many mentioned: the bleach

I was using ECN-2 Potassium Ferrcyanide bleach. When I tried C-42 with RA bleach, it worked as expected. Oddly, When I tried re-bleaching my dark tests in RA, there was no change, so this took a while to figure out--I was just about to give up when I got ahold of some RA for one more test.

The C-41 Potassium Ferrcyanide bleach formula differs from the ECN-2 formula. It could be that was also the problem. If I ever test the C-41 Potassium Ferricyanide formula with these developers, I'll repost the results. But in the meantime, if anyone has come this far with this problem: don't use ECN-2 Potassium Ferricyanide bleach with C-29 or C-42.

Thanks for the help! Happy mixing!

 

[mohmad khatab]

If anyone comes across this thread, I'm back with the solution.

As many mentioned: the bleach

I was using ECN-2 Potassium Ferrcyanide bleach. When I tried C-42 with RA bleach, it worked as expected. Oddly, When I tried re-bleaching my dark tests in RA, there was no change, so this took a while to figure out--I was just about to give up when I got ahold of some RA for one more test.

The C-41 Potassium Ferrcyanide bleach formula differs from the ECN-2 formula. It could be that was also the problem. If I ever test the C-41 Potassium Ferricyanide formula with these developers, I'll repost the results. But in the meantime, if anyone has come this far with this problem: don't use ECN-2 Potassium Ferricyanide bleach with C-29 or C-42.

Thanks for the help! Happy mixing!

My brother, Mr. Memphis.. In fact, this is an old pharaonic name.
Conclusion :
Mr. Stephen's recipe, whatever its name is (C29), even if it is scientifically correct, I declare that I absolutely hate it.
In fact, I did not see any good from that recipe at all in my professional career, on the contrary, that recipe was in one way or another a reason to stumble my career greatly,, I will not talk about the scientific or technical side,, I am here talking about the psychological side ,,
- My career went in the right direction when I started using that unknown and submerged recipe, which some describe as an unsophisticated and primitive recipe,,, and a recipe that will be objectionable to many.
But what matters to me is that it has proven to be a very balanced formula and the important thing I noticed is that this formula lives twice as long as Mr. Stephen's recipe, and as I thought about it, I found that it was probably because it didn't contain the potassium iodide.

Zone V - C-41 developer.
deionized water...................800 mL
Calgon..................................... 2 g
Potassium Carbonate............. 32 g
Sodium Sulfite ........................ 3.5 g
Potassium Bromide ............... 1.5 g
Hydroxylamine Sulfate .............. 2 g
CD-4 ........................................... 5g
Potassium Hydroxide .............. 0.5 g
You are not required to adjust the pH.
I noticed that the best results I got were with a temperature of 37.8
I prefer to use cheap copper bleach.

 

[Rudeofus]

Ron Mowrey (aka PhotoEngineer aks PE) recommended a clearing bath between color development and ferricyanide bleach. Typical compositions for a stop/clearing bath include 1% Sodium Sulfite or Sodium Metabisulite, and enough Acetic Acid to make the bath reek to high heaven. I would have thought, that a thorough wash between color developer and ferricyanide bleach would do the trick, but apparently this is not the case.

 

[mohmad khatab]

Ron Mowrey (aka PhotoEngineer aks PE) recommended a clearing bath between color development and ferricyanide bleach. Typical compositions for a stop/clearing bath include 1% Sodium Sulfite or Sodium Metabisulite, and enough Acetic Acid to make the bath reek to high heaven. I would have thought, that a thorough wash between color developer and ferricyanide bleach would do the trick, but apparently this is not the case.

Yes sir ,,
You're absolutely right .
This is the formula that Mr. PE gave me “may God have mercy on him”

pre-Bleach
---------------
sod. sulfite................ 40g
Acetic acid 28%....... 20ml
sod. Acetate .............30g
use sod. bicarbnate Or Acetic acid Addjust PH>>>> 6
Use this solution after washing and before bleaching for at least a minute and rinse the film after using it twice, it is used at room temperature.,
------------------------------------------------------------------------
Cleani Bath
----------------
Sod. sulfit.............. 15g
Acetic acid ............. 7ml
PH>>>>> 4.5
In all cases, this is an optional solution, but in the case of using copper bleach, this solution will be mandatory and not optional.
It is used after washing the film from the bleach. It is used for at least a minute. The film is rinsed twice after that.
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