Jobo CPE2 cleaning

[Kilgallb]

I noticed the second cycle of C41 development on my Jobo CPE2 with a lift has a different density. I finish with fixer or blix, but thought that maybe I am not cleaning the tube that dumps chemicals into the drum or out of the drum so blix or fixer is contaminating the developer on the next cycle.

Any advice on how to quickly clean the tube.

 

[mshchem]

I just pour a liter of water through it when I clean up, while cycling the lift.

 

[koraks]

I noticed the second cycle of C41 development on my Jobo CPE2 with a lift has a different density.

How did you determine this?
Before solving the problem, maybe we should understand it a little better.

 

[Sirius Glass]

I have found that the wash cycle of film or paper development sufficient to clean the lift delivery tube.

 

[Kilgallb]

How did you determine this?
Before solving the problem, maybe we should understand it a little better.

I mixed a C41 kit (Cinestill C41s 1litre kit) and developed 6 packs. Cycle 1 was one from each pack, one shot chemical use. I held the chemicals at 104F using an Anova Sous Vida cooker. The second batch were from the second backup exposure in the same packs. Same exposure.

The second batch had a different colour in the unexposed areas and scanned with a different colour cast (too magenta).

I had the same thing happen on the second batch using the new Kodak 2.5l kit.

Assuming I did not foul up the timings or temperatures, yes a big if, I am thinking I am somehow contaminating the developer with the last chemical used. In the case of the Cinestill kit it is the Blix, in the Kodak case fixer.

I do not do the final wash in the CPE2, but remove the tanks and do it under a faucet. Thus the reason I ma thinking it is the chemical delivery tube in the CPE2.

 

[mshchem]

This isn't rocket science, just wash out the lift. Also why are you using a sous vide for chemistry instead of the Jobo?

 

[Sirius Glass]

This isn't rocket science, just wash out the lift. Also why are you using a sous vide for chemistry instead of the Jobo?

I agree I use tap water and a sponge with a plastic scrubbing side.

 

[Kilgallb]

Here is a picture of the two Kodak process negatives on the light table.

 

[ic-racer]

I noticed the second cycle of C41 development on my Jobo CPE2 with a lift has a different density. I finish with fixer or blix, but thought that maybe I am not cleaning the tube that dumps chemicals into the drum or out of the drum so blix or fixer is contaminating the developer on the next cycle.

Any advice on how to quickly clean the tube.

4 changes of 1 liter water total, at the end of the process.

 

[Sirius Glass]

I agree I use tap water and a sponge with a plastic scrubbing side.

Also make sure that the tank is left empty of any water.

 

[koraks]

I finish with fixer or blix, but thought that maybe I am not cleaning the tube that dumps chemicals into the drum or out of the drum so blix or fixer is contaminating the developer on the next cycle.

Yeah, that's a possible problem.

Here is a picture of the two Kodak process negatives on the light table.

Which one is the first one you processed?
The bottom one definitely looks more cyan.
Inverted and (sort of, to the extent possible) compensated for the snapshot quality and backlight color, the color balance between the sheets doesn't look all that different:

The cyan density along the edge of the bottom sheet (red in the inverted file) can be a sign of insufficient fixing in that area. You could try and place a drop of fixer concentrate (C41 or B&W, doesn't matter) on the affected edge. Leave it there for 5-10 minutes, then wash the entire sheet. If you see the little dot where the fixer drop was as a lower density, more orange hue, then insufficient fixing was the problem.

Given the apparent pattern with a gradient of cyan density running into the frame and dropping away there, a light leak is another possible cause. Be wary of any red indicator LEDs etc. in your darkroom. Very bright white light filtering through black cloth (changing bag), film bags etc. can also show up as red fog (cyan density).

 

[Kilgallb]

The top one is the first one developed.

I need to think if my second sheet was fogged by my timer. Some detective work as I usually load the first sheets with no timers on, then load the second set while the first are in the fix. It might be I forgot to turn off the display on the timer (Graylab 540).

I ill try the fix experiment tonight.

Thanks for the suggestions.

 

[koraks]

display on the timer (Graylab 540).

I'm not familiar with this model; what kind of display does it have and particularly what color?

 

[Kilgallb]

Multiple big red LEDs.

 

[mshchem]

Multiple big red LEDs.

You can adjust the brightness, even turn them off.

 

[mshchem]

Is the Gralab 540 a process timer? I can't remember. I probably have one in my basement

 

[koraks]

Multiple big red LEDs.

Thanks for confirming; that does indeed match the color of the fog you're seeing. Which means that it may be the cause.

 

[Kilgallb]

I did another batch and carefully cleaned the tube after the fix by filling in 300 ml of water then spin the tank for 5 seconds then dump. I repeated this five times and the issue did not reappear.