4x5 negs flake in Developer!

[photoTEACH]

Hi I am a photography teacher, mostly Large Format. Today we processed 4x5 Ilford FP4 in D76 for 11 min. 1:1, and in 50% of the cases, the emulsion flaked off in the developer around the edges. I am used to seeing scratches and dings, but not edges that look all roughed up and disintegrated. I need to explain this phenomenon to the class, any ideas about what went wrong?
I know the most obvious answer is that the film was agitated too aggressively, but I am skeptical because it happened with such consistency.
Thoughts or Ideas??:confused:
Thanks!

[jetcode]

Hi I am a photography teacher, mostly Large Format. Today we processed 4x5 Ilford FP4 in D76 for 11 min. 1:1, and in 50% of the cases, the emulsion flaked off in the developer around the edges. I am used to seeing scratches and dings, but not edges that look all roughed up and disintegrated. I need to explain this phenomenon to the class, any ideas about what went wrong?
I know the most obvious answer is that the film was agitated too aggressively, but I am skeptical because it happened with such consistency.
Thoughts or Ideas??:confused:
Thanks!

sounds like old emulsion no longer adhearing to the carrier or a bad batch of film ...

[Kirk Gittings]

Welcome,

What was the development method? Trays? Tanks with hangers?

Any chance you could scan one of the negatives and post it here?

[David A. Goldfarb]

High temperature could be another problem.

[photoTEACH]

I can scan one of the Negs. It will take a day or two, but the temp was a strong, consistent 68 Degrees. I think if anything, there was a shift in the stop bath and fix, a variance of maybe 5 degrees. We were tray processing, the trays were older, could contamination be an issue? The only thing is, we had the problem, then didn't: then had it again, then didn't: zero consistency. And we used the same chemistry in all cases. ARG!

Thanks for the help! Any more ideas?

[Kirk Gittings]

I saw something a little similar once when I accidentally washed film in really hot water. The edges didn't "flake" but dissolved. Longer time in the hot water would have dissolved all of the image off the base.

[domenico Foschi]

This must be a defective batch.
High temp would dissolve the emulsion, the flaking is due to poor adhesion to the carrier.
Jetcode has suggested it could be old emulsion, but how old can it be, being FP4,...oh did you say fp4 or fp4 +?
Recently I cleaned a bunch of glass plates and many of them presented the flaked edge problem, but they were roughly 100 years old!
Could it be that the film was stored in adverse conditions?

[Gene McCluney]

If you are using fresh Ilford film, still in date, then regardless of whether it has been stored "too warm", it should not flake off in processing with common chemicals at a temperature of 68 degrees f.. Ilford and Kodak films are modern pre-hardened emulsions that are very resistant to such events. In the summer I have for the last 30 years successfully processed Kodak, Ilford and Fuji b/w films at temperatures slightly in excess of 75 f with no ill effects.

[Brian Ellis]

I processed at 75 degrees but never worried about the temperature of the stop and fix, I'm sure in my Florida darkroom it sometimes got well above 80 degrees with no problem. Black and white film is pretty hardy stuff. I think you got a bad batch of film. Quality control is going to be more and more of a problem IMHO as film sales decline and companies cut costs.

[Jim Ewins]

I mixed up some D76 @ 105+ degrees added a little cold water and forgot that it was hot when I developed some 4x5s and had no problems. I doubt it was anything but defective film.