


Thick as a Brickor, how to mix C41 chems
I've written here recently of my odyssey trying to find C41 chemistry that someone would actually ship to me (US), preferably Kodak Flexicolor, for use in a Jobo ATL1500.
Well, I got some from Adorama, but I'm having trouble figuring out what to do with it. I've downloaded and read the relevant Kodak publications, but no joyor else I'm just overlooking it. The bleach and fixer are straightforward, so no trouble there. The developer is the problem.
I have purchased the 5gal size Flexicolor developer replenisher (cat 191 9042) and the Flexicolor developer starter (cat 195 3009). (My preference would have been the 1 gal size of readytogo singleuse C41 developer but it's apparently discontinued.)
The replenisher looks straightforward: add the chems in sequence to 4 gal water then top up to 5 gal final replenisher solution. Easy enough. I have not yet figured out if it is possible to mix the stuff up a gallon at a time, or if I will have to mix up the entire batch at once. If so, one of those floatinglid containers will be the most practical way to store it I presume. (I bought the larger size solution because it is only a bit more expensive than the smaller sizes, and because I thought larger quantities would be easier to measure.)
Then of course I have to combine starter and replenisher to make the final working solution. Do I have this right: 126 mL (or 477 mL) water; then 14 mL starter (or 53 mL) straight from the bottle; then 860 mL replenisher solution (or 3.26 L); then top off to 1 Liter solution (or 1 Gal solution). I'm wondering how I'm going to mix quite that precisely!
Separately, do the starter and replenisher (after mixing from the components) solutions have any sort of decent shelf life, or should I just mix up a bunch of developer working solution, put it into the floatinglid container, and be done with it?
Thanks for any suggestions.

I can't help you with the specific quantities, since I've never used the Kodak C41 developers; however, I'd recommend mixing up just as much as you intend to use immediately prior to use. For mixing small quantities, try a syringe. You can find needleless syringes intended for measuring oral medications for infants and small children in drug stores. IIRC, mine goes up to 10ml, but I'm sure there are other sizes, too. You might also be able to find something in a kitchen store; I've got a similar syringe, but with a really blunt needle, that's intended for squirting stuff into meat as it cooks. (I'm a vegetarian and intend to use the one I found for a lemonade cake recipe!)

There is for sure a life span for mixed developer that is shorter than the chemical concentrates. I also use 3.5 gallon tanks for C41 and the mixing of the developer with available chemicals is hard, but not insurmountable. If you take the quantity of solution in each bottle..measure it in graduates then pour it back into the bottles. Now you know how much you have of each. A, B, C. etc. You should have written it down. Now lets say you have 1 gallon of component A (hypothetical). It (along with B & C) make a mix of replenisher to make 5 gallons. OK, divide 1 gallon (128 fl. oz) by 5, and you get how much to make a gallon. Now multiply this by however many gallons you want to mix up. You can use this formula to figure out the quantity of concentrates to make just about any amount. You can also use this formula to figure out small quantities take the fluid oz of the concentrate and divide it by the fluid oz of the quantity it is supposed to make. This gives you a fraction of an ounce of concentrate per oz. of made replenisher...then multiply it by the fluid ounces you wish to make. I keep a small calculator in the darkroom for this purpose.

Mike, if you get the plain developer, not replenisher, you do not need starter with a nonreplenished system.
If you do use replenisher and starter, there can be problems. IDK the real data on this as I always use the plain developer and no starter.
PE

Correct me if I am wrong, PE, but the starter is for deep tank processors who are continually replenished.
The starter has "conditioners" that stabilize the mix in the same way a fresh tank of developer would be after processing an arbitrary amount of film.
So you only need the starter if you are entirely dumping the developer tank of a machine or hand line and replacing it. It "seasons" the developer to be less active and helps it be more predictable in exhaustion rates.
At least, that is the way I understand it...

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Yes, the starter makes the original tank developer look as if it is seasoned.
It should therefore only be added to the proper Developer formulation.
PE

Mike,
Kodak tech publication CIS49 clarifies the mixing of less than full package quantities (page 4 for flexicolor chemicals), download it and all will be self evident. There is a copy of Z131 combined with all the relevent publications somewhere out there, just can't remember where.
Basically, you can mix replenisher, at the following rates (see CIS49, page 8):
Start with 700 ml of 8090 degree water, add (in order):
part A: 75 ml
part B: 12.5 ml
part C: 11.73 ml
Add water to make 1 l total volume.
Then take 860 ml of replenisher by , 14 ml of starter and add water to make 1 liter.
It is that simple, really. Once you get your had wrapped around all the little details, you'll start to get in the groove, then it starts to get fun.
On second thought, rather than have you google for hours, I have (temporarily) put the complete Z131 with relevent other tech pubs at http://www.eriepatsellis.com/z131.pdf (I'm thinking I got it from Dan Schwartz's site). Let me know when you get it and I can take it down.

Well, thanks everyone for chiming in with useful suggestions. I really appreciate it.
@Kino, @PhotoEngineer: no question, I'd rather have had the plain oneshot (for smalltank/rotary processing) developer that I have previously used, but I can't seem to find it anywhere that will ship to me. Are you saying that I do not need starter to used the Developer/Replenisher as a oneshot solution?
@erie, thank you very much, I have it. I thought I had downloaded z131 before, but my version/copy was incomplete compared to yoursmine had no information whatsoever about mixing partial volumes of packaged solutions. That is exactly what I was looking for, thanks! I'm guessing that tenthsofmilliliter precision is not called for here!
Great help everyone.

The developer does not use the starter. Other solutions may as defined by EK.
PE

Normally, the developer concentrates as shipped from Kodak will say Replenisher if they require Starter to make Developer. If it says Developer on the packaging, and does not say Replenisher, then it can be used without replenisher. The color replenisher chemicals that require starter to make tank solutions are E6 First and color developers, E6 Bleach, C41 Developer and Bleach. All the others just require a different dilution of concentrate to make either replenisher or tank solution. I can't speak for other brands, as I have always used Kodak product.

