Back to the original question..
I'm curious how you are using a Cibachrome tube at all for film. I received a couple yesterday, and they are absolutely smooth inside. My other recycled print drums all have ribs which keep the film backing away enough to let the antihalation coating get removed by a presoak. Does the fiberglass somehow lift the film away enough to do this?
Also, how do you keep the 4x5 negatives separated and affixed during development? All I can imagine is to lay the negatives out on a single piece of fiberglass, roll it up and put it in. But then I can't see how the film would stick when dry as it would be when you put it in.
Maybe I *can* use these drums with film developing after all!