C-41 Wash Temperature

[vijaylff]

Hi,

I'm about to try home C-41 processing of 4X5 for the first time, using the Unicolor print drum method. I'm going to start with the Unicolor 1 Liter powder kit. (I've seen the discussions over on apug where they talk about blix being inferior to separate bleach and fix, but I'd like to try this just to get the hang of the whole temperature control process.)

Anyway, my question has to do with the temperature for the water wash that happens between the blix and stabilizer steps. The instructions are ambiguous regarding the required temperature for this water wash. Does it need to be at the same warm temperature as the Developer and Blix? Or can it be room temperature water? How critical is temperature control for this wash step?

Thanks,
Vijay

[Henry Ambrose]

After the developer the temperature can wander a bit but keep the wash the same temperature as the developer and blix. You can stop heating your water bath that holds your chemicals after the developer step. If everything is 103 degrees (or whatever your kit calls for) when you put the film in the developer it'll still be close enough for the remaining steps. It takes a while for a large water bath to cool off enough to cause a problem. Unless you're working outside at the South Pole.
;>)

[Peter K]

Wash your films in water nearly the same temperature as the other baths because a sharp drop in temperature can ruin your films by reticuculation, this is a distortion of the gelatine by a course pattern.

Peter K

[Gene McCluney]

Wash your films in water nearly the same temperature as the other baths because a sharp drop in temperature can ruin your films by reticuculation, this is a distortion of the gelatine by a course pattern.

Peter K

It is very hard to get reticulation on modern hardened film stocks. Only "old style" films such as those sold as Efke and Adox are not pre-hardened. If a film can process at 100F, then it is pre-hardened. (This would be all E-6 and C-41 emulsions). Letting the final wash drop down to room temperature is OK. I don't have a Jobo, rather I use deep tanks in a water-jacket sink, with manual dip-n-dunk. I have always kept my final rinse/stabilizer at room temperature, as I didn't have enough room in the sink for that, and I have never experienced any reticulation in my 30 years of developing C-41. The only critical wash step (in C-41) and really not all that critical, is in the Kodak C-41 process, with the separate bleach and fix, there is a wash between bleach and fix, and this water should be similar in temperature to the bleach and fix, although all three can be somewhat lower in temperature than the developer, as they just work to completion.

[Bruce Watson]

You can of course do that if you want. But you should recognize that there are reasons to follow the manufacturers directions. One of those reasons is that the manufacturer didn't test it the way you propose doing it. So neither they nor you know exactly what's going to happen to the film if you wash in colder water.

The thing is that many chemical reactions are rate sensitive to temperature. Washing film is one of those. Much washing action is from diffusion - it takes some time for chemicals deep in the emulsion to make their way to the top where they can exchange with water molecules. How fast they move in the emulsion is somewhat temperature dependent. Once they reach the surface they'll only exchange if the concentration in the wash water is low enough, and that concentration is also somewhat temperature dependent.

What I'm getting at is that whether you'll wash sufficiently doing this is an unknown. It could be that just adding some time to this wash will be sufficient. It could be that making it a double wash (wash it twice with fresh water) will be sufficient. Without the lab, equipment, and time to do the research it's just an unknown.

On the reticulation front I agree with the others. You probably won't be able to induce reticulation easily; probably not going to be your problem.

I just don't want you to be screaming in 10 years when you pull this film out to use it and find that it's changed in strange and interesting ways. Which isn't likely, but possible. As long as you know the risks....

[Nick_3536]

Just follow the Kodak inscructions. They literally wrote the book. On their website should still be an Z document Z-131? Or was it Z-119? that includes all the temps for each step.

[vijaylff]

Thanks everyone for the helpful replies!

-Vijay

[SamReeves]

It is very hard to get reticulation on modern hardened film stocks. Only "old style" films such as those sold as Efke and Adox are not pre-hardened. If a film can process at 100F, then it is pre-hardened. (This would be all E-6 and C-41 emulsions). Letting the final wash drop down to room temperature is OK. I don't have a Jobo, rather I use deep tanks in a water-jacket sink, with manual dip-n-dunk. I have always kept my final rinse/stabilizer at room temperature, as I didn't have enough room in the sink for that, and I have never experienced any reticulation in my 30 years of developing C-41. The only critical wash step (in C-41) and really not all that critical, is in the Kodak C-41 process, with the separate bleach and fix, there is a wash between bleach and fix, and this water should be similar in temperature to the bleach and fix, although all three can be somewhat lower in temperature than the developer, as they just work to completion.

I agree. I just use room temperature for the final wash. Once your film has been fixed, there not too much that can happen to it.