JOBO reel slipped

[wilbur_wong]

I processed 4 x 5 negatives yesterday in JOBO drums using the 2509

sheet film reels. On one batch, one of the reels rotated fine during

development, but apparently stayed stationary (same side down) during

the bleach fix processing step.

 

On close inspection it seems that my 4 x 5 reels have a little bit of

friction over the central "post - filler tube" excepting the bottom

section of post I was using (with the little baffle and teeth). I

went to another tube section so I could finish my processing session.

 

Other then the light tight integrity of the system, I had not given

any thought to the reels needing a particular friction or locking to

either the post or to the drum itself to maintain proper agitation

movement. I would note that the particular drum I used is a number

2551 which does not have any separation ribs on its inner surface

which most drums do to help separate multiple sheets of paper. I have

used this system for years without any problems. There were film

sheets only in the outer 2 slots - none on the third inner slot.

 

The only other clue I have is that last week at the LF free workshop

it was mentioned that photo-flo permanently bonds to JOBO plastics. I

recently processed some b&w in my tanks and I might have used some

photo-flo in the tank. Since I seldom shoot black and white perhaps

that may have been the critical event.

 

Any one have any ideas about cause and future actions?

[donald_f_degen]

Wilbur, I'm a little confused by your question. Jobo reels do not rotate during processing, the whole tank rotates and the reel should remain stationary (in the tank). If you can rotate your reels with "a little bit of friction" on your center/fill tube, than your tube or reels need replacing. As the whole tank rotates, the reels (and film) rotate with it, the chemistry remains at the "bottom" of the tank. It is very important that the plastic film holders be used or inproper developing will result. I suspect that your reels did not turn with the drum, maybe the weight of only two sheets kept that side down, while the drum turned, resulting in improper agatation. Also, see the Jobo web site for info on NOT using Photoflo.

[wilbur_wong]

Donald,

I believe the one reel (there were 2 on the post and in the tank)stayed stationary and did not rotate WITH the drum. There were 2 sheets each on each side of the drum, so they were balanced in weight, inertia and hydraulic friction. The other reel in the tank rotated just fine. Also this is several batches later than any time that I might have gotten some photo-flo into the tank. I have measured the central posts with a caliper and the section on which the slippage occured is physically smaller than the rest of the post.

[neal_shields]

This sounds exactly like the problem that I kept having. Two negatives on the bottom reel on the same side not getting processed. Drove me crazy.

 

Everyone (almost) said that I wasn't using enough chemicals. I used more and the problem went away.

 

I can't explain why it always affected the bottom two on one side, but there is a stage in everyone's life where when you solve a problem, you don't ask why.

 

Jobo says to use about 1/2 of what everyone else says.

 

Neal

[jose_angel]

As I am so interested with the Jobo affairs, I will write my experiences.

 

I have find also a small rotation when testing the system by hand, but I wonder if the drum rotates during the process... I think that it doesn't. I think it is easy to lock the reel to the center post with a little "bricolage". The separation ribs of the inner surface of the drums doesn't affect the use for films. (All my drums have this separation ribs).

 

When I started developing films with the Jobo, I find sometimes some exposed parts on the film, but I think that it was produced before the developing process, when charging the film holders, or when discharging the holders to fill the Jobo drums... my darkroom were not absolutely ligth tight, and the changing bag is not absolutely "dark" also (zippers and arm tubes). Now, I take a great care when handling the film, and I don't find this problem again...

 

The ammount of solution used is exactly the recommended by Jobo, 270ml. for 6 sheets in a 2800 drum with the 4509n reel. Tmax RS 1+9. The emulsion side to the center of the drum.

 

About the Photo-flo, I never experienced a problem. I can't find in my old plastic drums (not Jobo) any substance on them, and I have been using some of them for more than ten years with the Kodak Photo-flo at 1:200. I believe that the plastic of this drums (the Durst 35mm plastic drum) are the same than the Jobo, but I'm not sure. Now I am using the Photo-flo in the Jobo drums only for roll films during 30 seconds, and inmediatly (once the film is out of the reel) I put the drum under the tap. With sheet film, I use a tray (I'm afraid of what I had read about it...)

 

Hope this helps,

[jose_angel]

I am absolutely impeccable with the charging of the Jobo drums. I put all the sheets with the emulsion side to the center, the reel with the plastic flaps in the --correct-- position, etc.

 

In an older post, we can read about an older Jobo sheet film reel, with a little differences (without the flaps?) that could cause other results...

[robert_lawrence]

Exact same problem, exact same cause with 12 sheets in an ATL-1500 - unfortunately it was someone elses shots. Your diagnosis is spot on in my case the fix was a new core from Jobo, no problems since. The spirals should NOT freewheel around the core during processing.

 

Robert Lawrence