C-41 (Lorr), I'm mixing Part C

[kmphoto]

Ok Folks..............
I have a over abundance of C41 (Lorr) developer with "bad" part C, so I'm mixing part C.

I am using this formula to mix the developer.
Stock Replenisher for 2 liters of solution:

Water 70-100 degrees 1600ml
Part A 160ml (Lorr) developer
Part B 25ml (Lorr) developer
Part C = 21 grams Sodium Sulfite
10 grams CD-4 (Photographers Formulary)
Water to make 2 liters
Ph 10.1
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I then use the required amount of stock solution and add "starter" to make 1 liter of working solution.
Adjust Ph to 10.1
I finish using C-41 Kodak stop, bleach & fix.
------------------------------------------------------------------------------
My Questions:
1) My negs seem to be lacking in contrast and a bit weak.
2) There seems to be a (color shift/cross over) to the magenta/green side.

Do you have any thoughts on this before I run another test????
Thanks for any thoughts.....

 

[RPC]

The Part C sodium sulfite of 21 grams is 10.5 grams per liter, which is quite high compared to the sulfite level in C-41 formulas I have used or seen, which is about 4 grams or less per liter. Sulfite is a preservative in developers but in color developers, too much will interfere with dye formation. That may be your problem. There may be sulfite in one of the other parts as well, probably part A. In Part C labels I have seen, bisulfite is present as well as CD-4, but not sulfite and certainly not that much. Where did you get that figure? Do you also add water to the stock solution along with the starter?

 

[Rudeofus]

I agree with RPC, this part C formula looks very odd. I would expect part C to contain CD-4 and a trace amount of Sodium Metabisulfite. You can probably leave out the Sodium Metabisulfite from your part C concoction if you mix fresh.

 

[kmphoto]

RPC, I’m not sure where I got that amount of sodium sulfite, I have a pile of notes print outs off the web.
I will remix, switch to sodium metabisulfite and cut the amount.
I recalibrated my Ph meter last night and found it was reading (+.10) to high.
I’m sure that’s part of it too.
Thanks for weighing in also Rudeofus…..

 

[Mr Bill]

I will remix, switch to sodium metabisulfite and cut the amount

No, don't use metabisulfite (nor bisulfite); this will lower the pH of your final mix such that you will have to make an upward adjustment. It's simpler to do as Rudeofus says, using only sulfite.

Like RPC says, color developers are sensitive to the amounts of sulfite, because it interferes with the formation of the color dyes. You need SOME to help protect the developing agent, but too much is also bad. So go by an actual formula; don't just wing it. It's probably ok to be off by ten or twenty percent, but not by a factor of two or three times.

 

[Rudeofus]

I actually recommended Sodium Metabisulfite over Sodium Sulfite if you want the part C concentrate to have meaningful shelf life. The pH change from 0.1 g/l Sodium Metabisulfite is almost none, given the presence of >30 g/l Sodium Carbonate. That's a mighty buffer!

 

[kmphoto]

Ok I understand.
I have both sodium sulfite and metabisulfite & can try it both ways in tests.

Kodak calls part C. 4-(N-Ethyl-N-2-hydroxyethyl)-2-methylphenylenediamine sulfate.
(I can’t even say it)………………..

One last question:
How many grams per liter of either chemical would be used, 4 grams???
Thanks

 

[Mr Bill]

I actually recommended Sodium Metabisulfite over Sodium Sulfite if you want the part C concentrate to have meaningful shelf life. The pH change from 0.1 g/l Sodium Metabisulfite is almost none, given the presence of >30 g/l Sodium Carbonate. That's a mighty buffer!

Hi, I should be clear that I'm specifically talking about mixing directly to a working replenisher (or tank solution), not trying to reproduce a part C for storage.

Also, I have not looked at the MSDS, which I'm guessing is what you're using to estimate the part C makeup. But if 0.1 g/l of the metabisulfite is all that's there, then I'd say it's probably not even worth bothering to add it to the working mix (again, I specifically am not talking about making a part C concentrate).

I have both sodium sulfite and metabisulfite & can try it both ways in tests.

Something to understand is that either of these will get you to the same result after adjusting pH. Regardless of which you use, if the solution is at a relatively high pH, most of it will be in the form of the sulfite ion. If you then lower the pH of that same solution, by adding an acid, then it will shift to the form of the bisulfite ion. And vice versa. So I just consider that if you add bisulfite to the high-pH color developer you may need to add something else to raise the pH back up. So I would personally just stick with sulfite for the addition, rather than metabisulfite (which, fwiw, gives the same results in a water solution as bisulfite).

How many grams per liter of either chemical would be used, 4 grams???

I'd say your best bet is to stick with the formula given here -
https://www.photrio.com/forum/threads/c-42-is-kodaks-home-version-of-c-41.89135/#post-1191785

But... the standard LORR package supplies all the sulfite you need. If, as Rudeofus suggests, there is only a tiny amount of sulfite ion supplied by part C (via the metabisulfite) then the obvious conclusion is that most of the sulfite is contained in another part, which you DO have. So I'm not sure that you even need to add any further sulfite. Note that I do not have any actual knowledge of the LORR packaging makeup; just suggesting something to be careful about.

 

[RPC]

If I read all the above correctly, I think the consensus here would be to simply mix as in your original post, but do not add any additional sulfite (all you need is probably in Part A), bisulfite or metabisulfte, then adjust the pH.

 

[Rudeofus]

Also, I have not looked at the MSDS, which I'm guessing is what you're using to estimate the part C makeup. But if 0.1 g/l of the metabisulfite is all that's there, then I'd say it's probably not even worth bothering to add it to the working mix (again, I specifically am not talking about making a part C concentrate).

If you look at Kodak's E6 5l Kit, it contains a bottle of 235ml CD part 2 concentrate. These 235ml of Kodak E6 CD part 2 concentrate contain roughly 41.5 g CD-3 and 1.5 g Sodium Metabisulfite. I would therefore not immediately dismiss that possibility out of hand. Obviously there can't be much more Sulfite/Metabisulfite in solution, since the low pH would drive out Sulfur Dioxide. This ridiculously low amount of Sulfite/Metabisulfite is not going to have much of a photographic effect, but it will likely prevent excessive oxidation of CD-3, the same way it protects lith developer from going bad too soon.

 

[Mr Bill]

This ridiculously low amount of Sulfite/Metabisulfite is not going to have much of a photographic effect, but it will likely prevent excessive oxidation of CD-3 ...

But Rudi, to be clear you're talking about making a Part C concentrate, right? I've not been speaking of the concentrate, but rather the actual working tank solution (or replenisher).

I personally would not try to make an LORR part C concentrate without seeing a good reason or benefit to it. There may well be some unexpected trickiness to it. Remember that MSDS don't necessarily show everything that's there.

 

[kmphoto]

From the original post:

I have changed things running new film tests with pretty good results.

For 1 Liter C-41 (Lorr)
Water 70-100 degrees 800ml
Part A 80ml (Lorr) developer
Part B 12.5ml (Lorr) developer
Part C = 5 grams CD-4 (No Sodium)
Water to make 1 liters
Ph 1.4

With all the input from you……..
I thought I’d try a scratch, with no sodium of any type for this test.
I figured I could add some if it didn’t work.

The test came out pretty good.
With no swing of color cross.

I know that this is not a purist mixture.
But I think I can make this work, perhaps with a tweek?

I guess...............?
"If, your happy with it, use it"…
If I come across something better....
I’ll let you know.