Problem with partial development on Paterson reels for 120 film

[brian_cannon1]

I've having a consistent problem, and I'm wondering whether others have faced the same issue: I only get about 8 good frames from developing 120 film on a Paterson reel -- the 4-5 frames on the inner part of the reel, i.e., the first portion of the film threaded in, are completely black. I'm using Tri-X and D76. The frames on the outside, i.e., the last ones to be threaded onto the reel, come out perfectly. I suspect I have somehow threaded the film incorrectly, but it's happened several times now. I've processed 35mm on Paterson reels in the past and not had this issue. Thank you for any input.

[Vincent Peri]

I've used a Unicolor Film Drum II for developing my film many years ago. The large tank will hold up to 5 or 6 35mm reels (memory fails me at the moment), and you need to put 5 ounces of developer in the tank for one reel, and 3 oz of developer for each additional reel.

For 120 film, I think it needs 7 oz of developer for the first reel and 5 oz for each additional reel.

 

The tank is placed lengthwise on a motorized roller for constant agitation, so if there isn't enough developer, the first frames inserted into the reel won't get developed. That's because the developer sits as a puddle in the bottom of the tank and part of the film dips into this puddle then rises out of the developer as the tank rolls on the motorized base.

 

I'm not familiar with the Paterson reels/tanks. If these tanks use inversion agitation, then I'm at a loss as to what's going on that the film isn't being developed at one end.

Wish I could be of more help.

Edited July 10, 2017 by Vincent Peri

[thirteenthumbs]

I use JOBO for 4x5, have the reels for 120 but prefer to use a stainless steel tank and reel for 120.

Many threads in the past that dealt with problems with Patterson tanks was the user left the center column out which caused a light leak. JOBO requires the center column to work properly also.

If you are putting the center column in, filling the tank with enough chemicals to completely cover the film and reel then before cutting the roll of film reinstall it on the reel or examine the film on the reel when you remove it at the end of processing look at the side of the reel against a light source. The film should have equal distance between the turns from outer to inner. If the space is not equal between the film throughout the reel you are either misloading it or the reel is defective.

[Dustin McAmera]

Black negatives could be caused by light getting into the tank. You're fitting the reel on the centre column, right? Do the black frames have clear edges? If so, it doesn't seem likely it's light leaking into the tank. Are you doing inversion, or using the 'twiddle-stick' for agitation?

 

I gave up on Paterson reels because I stopped being able to load them reliably. I think the ball-bearing parts of my reels got grubby and stopped moving easily. I use steel reels and tanks now. Anyhow, I think you'd feel if the film wasn't loading right, although 120 film is more likely to flex, being thinner.

[brian_cannon1]

I haven't been using the central column. That has to be it. (Sound of hand smacking head . . . ) Thank you very much everyone; I very much appreciate your quick responses.

[thirteenthumbs]

Yep, when all else fails read and follow the equipment instructions. :D

[luis triguez]

Rub with a candle of wax by all the rails. You will see how the film runs smoothly.

The candle sould be off, of course :)