Streaking prints with a Jobo???

[Martin L.]

This past weekend I did about 30 11x14 fiber print in jobo 2840 using suggested chemicals and speed 7 alternating rotation. Well, I used up all my stock of Agfa fiber so I switched to Ilford VC RC 11x14. Now I am getting ton of streaking in the prints like developer was dripped on and it ran down. The streaks always run down the length of the drum like as if they are happening when I am pouring it in. I have tried every variable that I could think of. I started using 500 ml of chemicals and was getting better results but now they have seemed to come back. I seem to get less when I use a slower rotation but I still get them. I have even tried a pre wash to wet the paper for more even chemical distribution. I have tried different developers and cleaning everything thoroughly between prints. Doesn't seem to matter. It is baffling me because I have read where this might happen with fiber prints but not RC as much. The main difference between the two is that the fiber was matte finish and the RC is glossy. I have a ton of paper that is glossy, I hope I won't have to tray develop it all. My darkroom is my basement and it is extremely hard to get a steady 68 degree temp. down there.

If anyone has had this problem and knows a way to solve it I sure would appreciate it.

[Nick_3536]

How well are you drying the drums?

[Martin L.]

How well are you drying the drums?

Probably not as well as I could be. There are a lot of nooks and ridges in there. It is an excellent point. I have 2 2840's so I will dry one more thoroughly while I use the other. That's really gotta be it though because I think I have tried everything else. I went back to the trays today after my post. At least everything came out well.

[Stephen Willard]

Let me see, it happened when you switched paper right? Perhaps your installing the new paper with the emulsion side facing outward toward drum when you should be installing the paper so that the emulsion is facing inward away from the drum surface.

Also you may want to check to see if the chemistry is flowing into the tank properly. Simply hold just the cover so that the inlet opening is facing straight up over the sink and pour water through it and make sure the water flows through the cover and into the tank properly.

You are doing something wrong, so it is just a matter of attacking the problem piece by piece until you figure out what is causing the streaks.

[Martin L.]

Stephen:

More good suggestions, thanks. The emulsion is facing in on both the fiber an RC. I have been thinking about this all day and I think that the only thing that changed (besides the paper) is that I may been setting down the cog top differently unknowingly keeping the water from draining until I snap it on. I am going to try your suggestion and see what happens.

[Nick_3536]

I know for colour I need to wipe the drum dry with paper towels.