Once again: streaks when developing *some* fiber based paper in Jobo 3063

[jose angel]

I`d say the tank is not leveled. There are clearly undeveloped areas in the same area in both prints, you mention at the bottom. The developer seem fine.
Looks like the tank is simply floating (or rotating out of axis). The tank should not float even empty. It must rest on the rollers and kept leveled all the time. Water should just lightly touch the tank.
You answered your question. Carefully check the lid. It's so easy to get it wrong.
Anyway; to my taste, 90 seconds seem a bit short for Jobo work. I know it is the recommended time and works for you, but... I don't like it... (maybe you can use up to 1:15 and extend the time). 16x20 is a big print.
(Why do you guys develop prints on a Jobo?... I need to see how prints run... !)

[Marco Annaratone]

I had something else to take care so I was not able to develop any print. But I will do it this weekend and keep you posted.

I will work first under the assumption that the problem has something to do with the drum floating and/or the cog somehow out of axis with the rotation. Then I will look at the amount of developer being used.

Thank you very much to all of you who provided suggestions and ideas. Yeah, developing paper - especially fiber-based - in a Jobo is certainly not ideal (by a long shot). I miss my trays and looking at the print appearing in front of me ... but right now the Jobo is my only solution.

[Cor]

When processing fiber paper in drums I do a pre- run with water (either dry paper in a dry drum and than add water, or, if I have a wet drum I wet the paper first in a tray and than shove it in, is fiddely though). The idea is that the prewetting allows a more even penetration of the devlopper..

good luck,

Cor

[tgtaylor]

Jobo does not recommend rotary processing fiber paper probably because, as pointed out above, fiber paper becomes heavier and limp when wet and has the tendency to fold over on itself. To prevent this use the clips that keep paper separate from each other. This may or may not work on a 16x20 sheet and would not be an option on 20x24.

Thomas

[Marco Annaratone]

After a few developments that worked just fine I concluded that it must have been too much water in the tempering trough and the drum was floating. The switch to a different paper coincided with the emptying and the refilling of the Jobo, hence the confusion

Anyway, I also played it safe and used 500mL instead of the 300mL I had been using with the Fomabrom.

Bottom line: lid of the drum carefully closed to avoid wobbling while rotating; keep the level of the water in the tempering trough in check, i.e., low enough not push the (bottom part of the) drum upward; use 500mL of development for 16x20 FB in a 3063 drum.

Anyway, let's see for how long that works

BTW, the Ilford Multigrade FB is 250 gsm, the Fomabrom Variant III is 180 gsm so - correct me if I am wrong - one shall assume that the Ilford will absorb (need?) more development soup than the Fomabrom.



Cheers

[Cor]

Which JOBO processor are you using ? Some years ago another photgraper told me that he ran his CPE withoy water (thermostat at the lowest setting !). Temperature is less of a factor for paper developement, if you work in a room , and pour in developper which is at room temperature: that shouldn't be the problem.

I guess that a drum in water has less friction, does less strain on the motor ?

Good luck,

Cor

[Marco Annaratone]

Which JOBO processor are you using ? Some years ago another photgraper told me that he ran his CPE withoy water (thermostat at the lowest setting !). Temperature is less of a factor for paper developement, if you work in a room , and pour in developper which is at room temperature: that shouldn't be the problem.

I guess that a drum in water has less friction, does less strain on the motor ?

Good luck,

Cor

It's a Jobo CPP2. I agree with you that having water in the tempering trough is not that important for paper development, considering the fact that my room temperature is always between 19C and 20C from October to April. When I measure the solutions before using them they are always ~20C anyway and the development time for paper is really short.