Questions about running C-41 for the first time

[williaty]

I am going to run C-41 with Kodak's Flexicolor chemistry set in a Jobo CPP-2 for the first time. I have a couple of questions about the process:

1) I've heard people running a 1-2% acetic acid stop bath after the developer. I know from talking to PE that it's not possible to substitute citric acid for the C-41 stop bath like it is for B&W. I have a hell of an aversion to acetic acid and don't really want to deal with it. Is there any benefit to inserting a single water rinse between the dev and bleach to help stop the dev and reduce carryover into the bleach if I'm not willing to go for a stop bath?

2) The Flexicolor instructions specify a wash between the bleach and fix and between the fix and stabilizer but I don't have any documentation on what it wants for these washes. Are we talking just cycle a tank or two of clean water through the Jobo or should I remove the tank from the Jobo and use the Jobo water-jet-on-a-hose-thing-who's-name-I-currently-can't-remember to cycle constantly running water through the tank for the specified duration?

3) Does C-41 benefit from 2-bath fixing (two baths, each for half the total fixing time, throw out bath 1 and move bath 2 up to the first position periodically) like B&W film does?

4) How much (volume in mL) developer, bleach, fix, and stab do I need to use per 8x10 equivalent unit of film?

 

[markbarendt]

Kodak's instructions work perfectly, follow Kodak's instructions and don't sweat the details.

 

[chassis]

williaty, congratulations on your journey into C-41. I processed my first sheet of 4x5 C-41 a few weeks ago and am hooked.

1. In my opinion a 100 deg F water stop bath after the developer would work. Not as well as a dilute acetic acid stop, but better than no stop, from a chemical crossover point of view. One suggestion is to use 2 water stop baths at 100 deg F of 1 minute each. This gives a change of water.

2. For my wash steps I use 3 minutes each at 100 deg F with distilled water.

3. I have no experience to offer.

4. Depends on your development hardware, whether it is a tube, drum, etc. For 4x5 I use the smallest Paterson tank, which is around 750ml. So for me that is the answer. The attachment is from Photo Engineer and shows capacities. You can calculate minimum required volumes from this, and make a decision based on your equipment.

 

[Gerald C Koch]

As far as the worry about acetic acid, do you eat salads? Vinegar is dilute acetic acid usually 4 to 5%. Diluted 1+1 white vinegar makes a good stop bath. Years ago Kodak determined that 28% acetic acid was safe for the average person to handle. If you use something stronger just use a bit of care. Use goggles and gloves when handling acids.

BTW, citric acid is a stronger acid than acetic is. It just doesn't smell.

 

[williaty]

No, I don't eat vinegar and refuse to be around anyone who's got much of it in their food. I'm not concerned about the safety of acetic acid. The smell of it, even in fairly low concentrations, makes me violently nauseated.

To the person who suggested reading the instructions from Kodak the problem is that, currently, the instructions from Kodak on this aren't available and the snippets posted here on APUG don't clarify what Kodak considers a wash.

 

[RPC]

1. In my opinion a 100 deg F water stop bath after the developer would work. Not as well as a dilute acetic acid stop, but better than no stop, from a chemical crossover point of view. One suggestion is to use 2 water stop baths at 100 deg F of 1 minute each. This gives a change of water.

A water stop bath after C-41 developer is not recommended. It won't actually stop development in the film but slow it; and at different rates in the emulsion layers, so crossover is possible. Go directly into the bleach if a regular stop is not used.

 

[EdSawyer]

Agreed, just bleach right after dev, it works great. Bleach can be regenerated, and dev should be 1-shot anyway (IMNSHO). The full Z131 manuals are available online, and cover all of this.

 

[sfaber17]

Right, you don't need a stop bath unless it is the old type of bleach (C41RA bleach is the latest) or ferricyanide homemade bleach.