Is there value to an actual "acid stop" in my stop bath when doing C-41?

[rpavich]

I have been assembling the chems and procedure for doing ECN-2 and noticed that the directions I'm following call for a vinegar+water stop bath.

I have been doing C-41 with a water only stop but this made me wonder if there would be value to doing it with the vinegar+water?

 

[RPC]

A water-only stop with C-41 is not recommended. It will not stop development in the three emulsion layers evenly, if it stops it at all, and can cause crossover. If you use standard C-41 bleach you can go directly into the bleach and a stop is not necessary, although many use one. Vinegar plus water to form a 2% acid stop will work fine. Use white vinegar only, not the colored kind. A ferricyanide bleach would always require a stop.

 

[rpavich]

A water-only stop with C-41 is not recommended. It will not stop development in the three emulsion layers evenly, if it stops it at all, and can cause crossover. If you use standard C-41 bleach you can go directly into the bleach and a stop is not necessary, although many use one. Vinegar plus water to form a 2% acid stop will work fine. Use white vinegar only, not the colored. A ferricyanide bleach would always require a stop.

Well thank you very much for clearing that up!

I will definitely stop doing the water stop thing after development.

My workflow is:
water + Washing soda shake like the dickens to remove remjet. Wash several more times until the water is clear.

Dev 3m 15 sec

Water wash/stop

Bleach 3m

Water wash/stop

Fix 6m

Ilford washing routine

Remove residual Remjet via running water and microfiber cloth.

Stabilizer

Dry negs

 

[Rudeofus]

One more thing: Kodak's ECN-2 process manual suggests a stop bath made from Sulfuric Acid, not from Acetic Acid, see here on page 7-29.

 

[iandvaag]

Not to hijack this thread, but could I use sodium bisulfate for ECN-2 stop? I don't have access to sulfuric acid AFAIK. I've asked around and no one seems to have battery acid either. If I can't use bisulfate, I'll have to use an acetic acid + sulfite stop with an extended wash and hope for the best. (I'm using a ferricyanide bleach)

 

[RPC]

Just thinking, I thought the OP meant C-41 all the way, i.e., C-41 film in the C-41 process but if he meant ECN-2 film in C-41, then yes, sulfuric is used from what I have heard.

 

[rpavich]

Just thinking, I thought the OP meant C-41 all the way, i.e., C-41 film in the C-41 process but if he meant ECN-2 film in C-41, then yes, sulfuric is used from what I have heard.

I meant c-41 process for c-41 film. I only mentioned ECN-2 because I am going to be trying that process also.

 

[RPC]

I meant c-41 process for c-41 film. I only mentioned ECN-2 because I am going to be trying that process also.

I began to wonder because in your workflow you listed remjet removal. C-41 has no remjet.

 

[rpavich]

I began to wonder because in your workflow you listed remjet removal. C-41 has no remjet.

That particular comment was in reference to the ECN-2 question but the workflow that I was wondering about when I posted the question was the C-41 which was just water.

 

[darkroommike]

A stop bath is a good idea for C-41 if you reuse your bleach and fix (or blix) so that the pH of your bleach doesn't change from developer carryover. A replenished line (with proper q.a. with a densitometer) doesn't have this problem since the bleach replenishment rate is high enough to handle the carryover and usually has some sort of arrangement to minimize developer carry over.