C41 Bleach time with diluted Bleach?

[AlbertZeroK]

So, I have a photo therm, but can only save either E-6 or C-41 bleach. I'm thinking I have 55L of C-41 bleach concentrate (don't ask) and just a cube of E-6, so I'm thinking of using the C-41 bleach at a lesser concentrate.

So if I mix the C-41 bleach at half normal strength and double the bleach time, would that work? I mean, bleach runs to completion, so could I just adjust my bleach time to say 10 minutes or 15 minutes and use half strength bleach?

 

[brucemuir]

55L of C41 bleach?
Let know know if you want to get rid of some and what type it is (Koadak BleachIII ?)
Im in MD so it may be doable if you're game.

I can't answer your question and although it seems bleach capacities are conservative I wouldn't recommend half strength but I don't know the chemical processes well enough... so take it with a grain.

You can still find regenerator for C41 bleach but IDK if if E6 bleach can be regenerated as easily.
Regeneration is similar to replenishment as it replaces depleted ingredients in the bleach and then you aerate it also, I'm assuming to add oxygen.

You may need to do a slight PH adjustment to regenerate C41 bleach but I misplaced this critical info.
I did manage to score some C41 bleach regenerator but have not used it yet.

 

[Athiril]

Why are you wanting to dilute it more? Just mix it up as you need it.

 

[stefan4u]

C41 Bleach for E-6 Films

High Albert !!

I do use my c-41 (mydoneg air bleach III) for e-6 as well. But in the opposite to your attempt I take regular strength and prolong the bleaching time up to 8-10 min. This will do it for me, Dmin is at it’s level…

I would not dilute the c41 bleach, it has to work hard. In opposite to negative Film all silver is developed and has to rehalogenated by the bleach in order to get solved out of the layers by the following fixer. The least you can do is prolonging the reaction-time to give the (slightly weaker) c41 bleach the opportunity to do it’s job.

Edit:
If you want to increase the lifetime /”mileage” of your Bleach simply regenerate it. Depending on the product you have to add only a small amount of regenerator. I double this amount due dilution in the reel tanks. In my case this will be only 30 ml /135 36exp.

Look out for some datasheets of your bleach and regenerate it. Oxygenate it with a aquarium bubble stone prior use, it will live nearly for ever… (only valid for reddish Fe EDTA bleaches, don’t oxygenate these greenish ammonium nitrate rapid bleaches)

Regards,
Stefan

 

[AlbertZeroK]

Why are you wanting to dilute it more? Just mix it up as you need it.

I want it to last longer. This stuff mixes up 2.8 L Bleach + 1 L water, so it won't last as long as you'd think.

55L of C41 bleach?
Let know know if you want to get rid of some and what type it is (Koadak BleachIII ?)

It's Agfa CN-Bleach. I would suggest keeping your ear to the ground for stores that are discontinuing film developing, that's where I picked up cubes of E-6 Chemistry. The Agfa CN chemistry I picked up at a pawn shop who got it from a lab that went out of buisness years ago. Both discoveries because I have a ebay search that emails me whenever certain chemistry shows up on ebay.

 

[AlbertZeroK]

High Albert !!

I do use my c-41 (mydoneg air bleach III) for e-6 as well. But in the opposite to your attempt I take regular strength and prolong the bleaching time up to 8-10 min. This will do it for me, Dmin is at it’s level…

I would not dilute the c41 bleach, it has to work hard. In opposite to negative Film all silver is developed and has to rehalogenated by the bleach in order to get solved out of the layers by the following fixer. The least you can do is prolonging the reaction-time to give the (slightly weaker) c41 bleach the opportunity to do it’s job.

Regards,
Stefan

So you use c-41 bleach undiluted for both c-41 and E-6 ? I've heard that's not the best idea. I think the old SK4.3 photo therm did the same thing...

 

[stefan4u]

High Albert

This may depend on your product and processing times, but the way I do it with my chemicals it works simply fine. Quite a time ago I had a e-6 homebrew phase. During measuring all the test stripes / control patches with a densitometer I found that the bleaching step was no problem. But I have to admit that my bleach may be a bit stronger than original due overreplenishment (to prevent activity loss by dilution by residual rinsing water)

Simply give it a try with prolonged bleach time (and well oxygenated) and do a test at your own material.

Regards,
Stefan

 

[Athiril]

I wouldn't dilute bleach, I don't think you'll get more mileage out of it, just longer processing times.

Develop->Stop->Rinse->Bleach may get more use out of it then simply Develop->Bleach

 

[stefan4u]

I wouldn't dilute bleach, I don't think you'll get more mileage out of it, just longer processing times.

Develop->Stop->Rinse->Bleach may get more use out of it then simply Develop->Bleach

I’m absolutely with you, no dilution al all.

But somehow I’m not sure of Albert’s intention. The way I understood him he does have a large amount of C41 bleach but only one packet of E-6 bleach. I assumed that he wants to use C41 bleach for E-6 processing, that’s the reason for my previous postings…
Can anybody enlighten me

Regards Stefan

 

[AlbertZeroK]

actually, my phototherm allows me to save one chemical, I'm going to save E-6 bleach and use c-41 bleach one shot. Thought if I diluted it, my supply would last longer. Might just put a valve on the save line and save both bleaches.

 

[Photo Engineer]

I would not dilute a C41 or E6 bleach to the wrong concentration. I would be careful using C41 bleach for E6, as the pre-bleach introduces a precursor to formalin and some other goodies which are to be activated by genuine E6 bleach. IDK if C41 bleach will do this properly. Therefore - watch out.

PE

 

[2F/2F]

I want it to last longer.

You have 55 L of the stuff, and each 3.8 L of working solution (2.8 L of concentrate) will last you for 120 rolls, without regeneration. This means that you have enough bleach to process over 2,350 rolls of film. Even if you only use it to half it's capacity, you have enough for almost 1,200 rolls. I'd look to save your money in other areas, most importantly shooting a higher percentage of "keepers." Try not taking a shot unless you really think you are going to want to print it. Stretching you chemistry is not a good way to gain economy IMHO...especially with the sensitive color processes, as opposed to b/w.

 

[stefan4u]

Oh my god, why one shot???

Bleach is not only the most expensive part in Processing but luckily the most stable part too.

If you do have minilab chemicals they are probably replenishable. Assuming a replenishing rate of 50 each 135 / 36exp. Film (which would be indeed very high) these 55 Liters (of replenisher) would be good for about 1100 films!! I think because of that amount I just could not imagine, how thinking about dilution to increase the “mileage” would make any sense … (sorry)

I would call this a lifetime supply, don’t toss it.

Simply try it with extended times for E-6 processing too; if you are in luck your phototerm chemical-saving-problem will be solved this way round.

Regards Stefan

 

[brucemuir]

I agree with replenishing/regen the C41 bleach.
It is getting hard to come by and shipping the stuff is even worse.

Stefan,
do you know anything about adjusting PH of used bleach when regenerating?
I had a datasheet for the Bleach III regenerator that I think I saw this but now I can't find it.
(it's not the readily available tech pub for this product)
Maybe I'm being unnecessarily paranoid.

I seem to remember you needed to get the regenerated stuff in the mid 6.4-6.7 range but I am guessing and plan to use the Kodak Flexicolor Bleach III Regenerator soon.

 

[Photo Engineer]

Bruce;

I don't remember the pH of Bleach III, but the old bleach was about 6.5.

In any event, the pH is adjusted with Ammonium Hydroxide or Acetic Acid. Both can be had or made up to equal concentrations. I would use the 28% NH4OH and 28% HOAC for this to get to the right value for the bleach you are using.

I posted some formulas here for the original bleach. You can use either of the two methods.

PE

 

[brucemuir]

PE.
I was hoping you'd see my distress

When I was researching the regen I came across some old patents and also some datasheets and these all mentioned a PH adjustment was needed.

I don't think the main Kodak TechPub for the Bleach III regen mentions it though.
Maybe the regenerator has this adjustment built into the formula.
I plan on testing before I use the regenerated bleach for anything decent obviously.

Thanks as always.

 

[stefan4u]

Bleaches tend to work better / faster in slightly acidic milieu, My mydoneg air bleach III shall be at pH 4.50 (+- 0.2) for the seasoned solution. Because of slightly over replenishing it dropped to around pH 4 if I measured it once. Increasing the pH again to pH 4.5 with NAOH solution made no visible different at all. I decided to let it go now…

Again, this is is only valid for my used products

Kodak bleach III (seasoned Tank solution) should be around ph 4.5 and 5 too, newer sources say pH4,75 (+- 0.25)

Google for Kodak cis-61 “Specific-Gravity and pH Measurements of KODAK Processing Chemicals”. Depending on the year of that data sheet you can get slightly different values.

Regards Stefan

 

[Photo Engineer]

The pH of the C41 bleach has been varying over the years to match the film dyes. At one time, if the bleach was too acidic, you could set up a redox reaction between the bleach, the silver and the cyan dye and end up with a leuco (colorless) form of the dye. At that point, your negatives (or slides if you tried this with E6) would be too red. To fix this, you would then have to treat with a ferricyanide oxidizing bath to reform the cyan dye.

So you see, this is not a simple matter - playing with your bleach and the bleach pH. I suggest measuring the pH of fresh bleach III and then as you work, you adjust the pH back to that value!

PE

 

[AlbertZeroK]

The other reason for one shot is that I want to pay around with developing movie film. my calculations with the photo therm, I should get over 600 rolls with my supply, which is far less than I'd like, considering I have enough developer for 80L of developer.

 

[Athiril]

I would not dilute a C41 or E6 bleach to the wrong concentration. I would be careful using C41 bleach for E6, as the pre-bleach introduces a precursor to formalin and some other goodies which are to be activated by genuine E6 bleach. IDK if C41 bleach will do this properly. Therefore - watch out.

PE

I've tried it. You get left with brown film + streaks, which then you need to bleach with fresh beach.

With C-41 bleach (Flexicolor Bleach III) you have to rinse/wash after colour developer, skip the pre-bleach, do the bleach, and run a stabiliser at the end.

 

[Athiril]

The other reason for one shot is that I want to pay around with developing movie film. my calculations with the photo therm, I should get over 600 rolls with my supply, which is far less than I'd like, considering I have enough developer for 80L of developer.

ECN-2 film is absolutely terrible (image quality & density) when run through C-41, I've done it most recently with 5201 50D. ECN-2 developer is dirt cheap. Even here in Aus. What you have to do is get the price sheet, which I've found for the US on Kodak's site after much digging and was sent the Aus version by a rep.

You then have to special order it via someone with a Kodak account, ie: any of the retailers, such as B&H (or Vanbar, etc here in Aus, anyone who gets Kodak stuff from Kodak). Ask them to place a special order and give them the Kodak Catalogue numbers for what you want.

It has a replenishment rate listed in the ECN-2 process specifications for all bathes, which includes recipes to make them (or you can use kit chemistry), so you can use and replenish a ferricyanide bleach if you wish (details are in ECN-2 process specifications).


From my first rough calculations of trying to break it down. I started with;

826mL H2O
212mL A
56mL B
*
75mL Starter
300mL H2O
= 1.5L tank solution, roughly.

* = stop there for replenisher (~1.125L worth), if I understand correctly, the replenisher isn't simply working solution sans starter, it's less diluted. This may be due to water carry over in large amounts from the last rinse before developing when processing long lengths (such as 1000 ft)

Part A is quite heavy, as it's ~20L worth of concentrate, it's a tad difficult to pour out into a measuring cylinder for small amounts, but doable.

I made my own starter, and pH was slightly high around 10.6 or so, which needed dropping with Sulphuric Acid, the aim is 10.32 iirc. Starter is nearly $80 here, as opposed to around $20 last I checked for the U.S. I was planning on replenishing so my working solution should improve over time.


Kodak probably have info on mixing smaller amounts somewhere.


One of the first tests, mixed to the above amounts, with Stabiliser III run at the end, and using C-41 bleach (stop and wash after the dev though, not straight in).

Remjet doesn't fall off the film in an alkali bath like with the old 500T, much of it stays on. I use nitrile gloves and squeegee it off with my fingers several times, rinsing/rubbing fingers together in the stabiliser III bath I just pulled it out of to wash off the rmjet off the fingers, you have to do it several times to get rid of it all.




50D in ECN-2 test #1 by athiril, on Flickr

 

[Photo Engineer]

Somewhere, with E6 films, you must introduce formalin or the E6 film will fade.

PE

 

[Athiril]

Stabiliser III for C-41 contains it, which was why I said stabiliser at the end bath

 

[Photo Engineer]

It has become reflex with me because so many people tend to omit it!

PE

 

[Athiril]

Sounds like you need a few hot keys for some pre-made responses