Fogged film; detective work needed

I am probably overlooking something obvious but I need some ideas. I have just developed 3 rolls of 35mm film which was loaded into cassettes from a bulk roll, They were developed together in a large Patterson tank. I also developed a roll of 120 film in a single tank in the same session.
Both tanks were loaded in a light tight darkroom.

The 35mm cassettes were exposed in the past two weeks, the 120 was exposed several months ago.

Now the results. ALL FOUR ROLLS were fogged severely for about 1/3 of their length FROM THE beginning of the rolls. The remaining lengths were still fogged but decreasingly so. Even the least fogged end (the film near the end of the strip, (chronologically) had some fogging of the edges (i.e. the perforations on 35mm).

The fact that both film formats were fogged at the same end, even though 120 finishes up reversely wound to the 35mm film, precludes fogging after the film was exposed. The 35mm rolls were shot with a Canonet with good seals and no history of fog. The 120 was shot with a Hapo 66 which has not produced this result before.

Very grateful for suggestions. Thanks
John

Did you load the reels onto the center column? There's a center column that prevents light from going into the tank.

Different film stock, exposed in different cameras and developed in different tanks. The only common factors I can think of are (a) the darkroom and (b) the chemicals. As far as chemicals go, any chance the fixer was exhausted? I have no experience of this, but should imagine it could give results similar to fogging if the fixer is not working as fast as expected. No idea why it would only affect part of the film, though.

edge-t said:

Did you load the reels onto the center column? There's a center column that prevents light from going into the tank.

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A great suggestion. However the 35mm film would be loaded with its lead at the center of the developing spool, but the end of the 120 film would be at the center. I would expect that leaving out the spool would fog the film at the center of the spool mostly. That would mean the start of the 35mm and the end of the 120. And it ain't so!

I have checked out my "drying tray" and the two center columns are there. I am almost certain I loaded the three 35mm spools on a column ( at 71 years old one never says "absolutely certain"). I just may have not used the column on the 120 film. I really like your suggestion. It is so good I am having real doubts about those columns. In many years of film development I have never missed using them.

Anyone got another suggestion that will explain the results.

Thanks
John

Maybe you could have tore out the 120 from the backing paper before loading it---masking tape side first, since you're 71. just saying. Ha... other than that, I cant think of any other reasons the film would fog up as you described.

edge-t said:

Maybe you could have tore out the 120 from the backing paper before loading it---masking tape side first, since you're 71. just saying. Ha... other than that, I cant think of any other reasons the film would fog up as you described.

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Bingo! You have it. I do load the masking tape first, always. Now I am convinced. I will run a few tests in the next few days and try and reproduce, and correct, the error. Thanks loads.

I am relieved but ticked off that I made such an elementary error.

Best wishes.
John

jtcliff said:

I am relieved but ticked off that I made such an elementary error.

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John, use stainless steel tanks. No center column to forget. And they use less chemistry which helps if you're using one-shot stuff. Yeah, they require more dexterity to load, but if the dexterity is still there, I find them easier to load than a Paterson.

Mark Overton