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

[Marco Annaratone]

Really frustrating. I read all the old posts on the subject, I am aware that Jobo and fiber paper are not a happy couple, and yet I cannot figure out what's going wrong.

Let me say right away that I rinse and dry perfectly the drum before using it, so water marks are *NOT* the problem. It really looks like streaks from the development soup.

Jobo 3063 drum, 16x20 prints. Neutol 1+7, 90s, 320mL. Rotation 'P'. Development of 16x20 prints with Fomabrom Variant 111: no problem.

Yesterday I moved to Ilford Multigrade IV FB. Same 16x20, same development. In the last 8 inches of the print (i.e., the part deep into the drum) I get horrible streaks in the direction of rotation. I increased the development soup to 500mL (same concentration and time) and the print came out perfect. So I printed a second one half an hour later again with 500mL: horrible streaks.

WTF?

Has someone tried to develop fiber-based paper in the Jobo with much lower concentration and longer times? If that is at all possible it may improve the situation ...


THANKS!!

[Oren Grad]

Can you show us what the streaks look like? Is the pattern the same from one spoiled print to another?

[Jeroen]

Fibre paper will expand when wet, period. A different brand & type of paper may expand more or less (Fomabrom vs Ilford Multigrade). Try using more developer (500ml, or more) and see what happens. Tray development would always be preferable, but perhaps you lack the necessary space in your darkroom for 50x60cm trays.

[Pere Casals]

but perhaps you lack the necessary space in your darkroom for 50x60cm trays.

Trays can be stacked in a rack:


http://www.studioindiana.com/About/J...er,darkro.html

[Marco Annaratone]

They are different.


https://postimg.cc/yD9xsdVY


https://postimg.cc/Snz2RdG4

[Marco Annaratone]

Trays can be stacked in a rack:


http://www.studioindiana.com/About/J...er,darkro.html

Unfortunately not in my bathroom.

[Marco Annaratone]

The two prints - one screwed up, the other just fine - have been exposed and developed within 30 minutes from each other with the same, "identical" procedure. Clearly it was *not* identical, otherwise the result would have been the same ...

Thinking outside the box, two things might have been different.

One, how precise was the fit of the cover of the drum to the drum cylinder itself? If the fit is done carelessly the drum wobbles while spinning in the Jobo. Maybe the wobbling generates uneven distribution of the chemistry.

Two, the level of the water in the Jobo might have been different in the two prints. If there was too much water the drum would start floating over the water while spinning, and tilt toward the head of the Jobo thus making it more difficult for the chemistry to reach the bottom of the drum in an even way. I always check with a spirit level how horizontal the drum is before starting the development. But I do it before letting water in.

These are two really wild guesses, but at this point I do not know what to think.

[Pere Casals]

Did you use "automatic reversal of rotation during processing" or not ?

[scheinfluger_77]

Is the drum rotating when you pour in?

[Fred L]

I dunno, but that doesn't sound like enough developer for 16x20 fiber prints. I don't use Experts for paper but I'd probably start with 1 litre. You're reusing it anyways right ?