Strange Dark Fluid Streak on Negatives

[koraks]

I read your post, but I dont get the argument about dilution. You typically use photoflo in a dilution of something like 1+200. Not really an issue.
In the linked thread you can see that current conditioners are essentially an antifungal compound (the 'important extra') and a surfactant. There's no reason why photoflo couldn't act in the latter role, as you also suggest. Whether the antifungal/antimicrobal compound is necessary is debatable if you take into account proper storage conditions.

 

[pwadoc]

The late Photo Engineer started a very good thread on the issue of stabilizers. It may prove useful:
https://www.photrio.com/forum/threads/the-definitive-word-i-hope-on-color-stabilzers.89149/

Thanks, that's super helpful. I also seem to recall that the final rinse soaks into the emulsion, rather than sitting on the surface (the emulsion is somewhat spongy), so I'm not sure photo-flo would affect it much, but I'm still going to eliminate it in my next batch to see if it affects the streaks.

 

[MattKing]

I read your post, but I dont get the argument about dilution. You typically use photoflo in a dilution of something like 1+200. Not really an issue.
In the linked thread you can see that current conditioners are essentially an antifungal compound (the 'important extra') and a surfactant. There's no reason why photoflo couldn't act in the latter role, as you also suggest. Whether the antifungal/antimicrobal compound is necessary is debatable if you take into account proper storage conditions.

I'm just saying that if you add, e.g., 250 ml of working solution photoflo to 250 ml of working solution final rinse, you end up with 500 ml of solution where the "important extras" in final rinse have been diluted to half strength.

 

[Truzi]

I think the issue of using surfactant after stabilization is the stabilizers may be leeched out because the Photo-Flo solution is mostly water. You wash away the stabilizers.
What I gathered from Photo Engineer's thread is that surfactant with stabilizer in it lets the the stabilizer do it's thing as well as preventing drying marks.

Pay attention to MattKing's very important comments about dilution. You want to make sure there is sufficient stabilizer in your last bath. When I first did c-41 I prepared a formaldehyde solution as Photo Engineer suggested, adding Photo-Flo to it but no additional water.

In other words, I added Photo-Flo concentrate to the "stabilizer," NOT working strength Photo-Flo. As a matter of fact I added less surfactant than the bottle states. I also compensated volumes to make sure I had sufficient formaldehyde concentration.

I've also had drying mark problems even with surfactant, so I use a bit less concentrate, but also let the reels sit on a towel (lint-free cloth) for a little bit before removing the film. This lets water flow a much shorter distance to the edge, so it's less likely to dry over an image. Someone here claims to use a salad spinner to get rid of excess water before removing the film.

 

[koraks]

When I first did c-41 I prepared a formaldehyde solution as Photo Engineer suggested, adding Photo-Flo to it but no additional water.

That's a straightforward way to do it. Albeit that the formaldehyde is no longer necessary for dye stability with today's c41 films.

 

[pwadoc]

I think the issue of using surfactant after stabilization is the stabilizers may be leeched out because the Photo-Flo solution is mostly water. You wash away the stabilizers.
What I gathered from Photo Engineer's thread is that surfactant with stabilizer in it lets the the stabilizer do it's thing as well as preventing drying marks.

Pay attention to MattKing's very important comments about dilution. You want to make sure there is sufficient stabilizer in your last bath. When I first did c-41 I prepared a formaldehyde solution as Photo Engineer suggested, adding Photo-Flo to it but no additional water.

In other words, I added Photo-Flo concentrate to the "stabilizer," NOT working strength Photo-Flo. As a matter of fact I added less surfactant than the bottle states. I also compensated volumes to make sure I had sufficient formaldehyde concentration.

I've also had drying mark problems even with surfactant, so I use a bit less concentrate, but also let the reels sit on a towel (lint-free cloth) for a little bit before removing the film. This lets water flow a much shorter distance to the edge, so it's less likely to dry over an image. Someone here claims to use a salad spinner to get rid of excess water before removing the film.

My approach with the photo flo was always to use it as a separate final dunk after the final rinse, rather than adding the photo flo to the final rinse solution. I think that should avoid dilution issues with the final rinse, though I guess it could wash some of the rinse solution off the surface of the film.

The one thing that makes me think that these marks aren't from drying is that they don't go away when I re-soak the film. I was under the impression that drying marks could be washed off, but maybe that isn't the case?

 

[koraks]

I guess it could wash some of the rinse solution off the surface of the film.

Indeed, the photoflo bath will largely remove the conditioner from the film, drastically reducing the utility of that step. Commercial final rinse baths already have a surfactant so additional photoflo is superfluous.
Most drying marks can be rubbed off with a soft cloth, tissue paper or even a finger.

 

[AgX]

My approach with the photo flo was always to use it as a separate final dunk after the final rinse, rather than adding the photo flo to the final rinse solution.

I am puzzled.
To my understanding the final rinse always is a rinse containing a surfactant. Thus succeeding it by another surfactant rinse makes no sense.

Furthermore, as already hinted at, such rinse may even hamper the intended effect of the original final rinse in some processes.

 

[MattKing]

If you insist on using photoflo as well, use it before the final rinse.

 

[Sirius Glass]

I am puzzled.
To my understanding the final rinse always is a rinse containing a surfactant. Thus succeeding it by another surfactant rinse makes no sense.

Furthermore, as already hinted at, such rinse may even hamper the intended effect of the original final rinse in some processes.

PhotoFlo is the final rinse for black & white film, not color film.

 

[mnemosyne]

Yep. The final rinse should be the last solution that touches the film. Unless it is overconcentrated or overdiluted or prepared with very hard tap water, you shouldn't see drying marks. I mainly use the final rinse that Fuji includes in the X-Press 5 liter kits and dilute it with demineralized water to working strength. It leaves perfectly clean negatives.

 

[AgX]

PhotoFlo is the final rinse for black & white film, not color film.

-) I reject that idea
-) even if would be so, the use described by pwadoc makes no sense

 

[AgX]

In the linked thread you can see that current conditioners are essentially an antifungal compound (the 'important extra') and a surfactant..

Both Kodak and Kodak Alaris describe their final rinses as essentially a surfactant and their biocide content aimed at stabilizing the working solution, not being aimed at preserving the dry film.

Years ago I had a discussion with an Agfa chemist at their processing chemicals plant on whether the biocide in their final rinse was just aimed in preserving the concentrate, working solution or he dry film.
And he had no idea.

 

[aidan175]

Hi, did you end up figuring out what was wrong? I am surprised by how little information there is about this issue online. I extended all wash times, bought new chems and everything and am still having the same issue as what you had here. I inspected the negatives before adding any sort of wash aid and it was there so I know that isnt the issue.

 

[pwadoc]

Hi, did you end up figuring out what was wrong? I am surprised by how little information there is about this issue online. I extended all wash times, bought new chems and everything and am still having the same issue as what you had here. I inspected the negatives before adding any sort of wash aid and it was there so I know that isnt the issue.

I'm not 100% sure what was causing it, but my best guess is that it was related to the way I was introducing the chemicals into the tank. Because I wasn't using a lift the tank wasn't rotating when I poured the chemicals in, which resulted in a transition area when the chemicals sat in the tank for the brief period before I could get the tank onto the machine. The CPP2 I was using happened to be part of an ATL-1 that I was in the midst of repairing. I put some additional effort into getting the ATL-1 head working, and since then the problem has no recurred.