Very weird. Just had this problem with a roll of Tmax 100 I developed on a steel reel yesterday. Although it showed uneven kind of mottled development all over it certainly had a pronounced over development on the edges. I struggled to get the roll on a 120 patterson reel and failed. I don't know if it was too humid in the changing bag or what. So I abandoned the Paterson reel and loaded the thing onto the steel reel. The problem with the steel tank is it takes longer to pour stuff in because it air locks if you are too aggressive. So developer and stop went in slow. The negative was a total write off. I was using pretty fresh stop and freshly mixed rapid fixer. The Xtol is a few months old but it beautifully developed a tmax 100 negative a week ago. I agitated pretty aggressively once a minute. 30 seconds initial agitation once the developer was in. Strange.
I expect that your agitation method may be at fault. There may be a language issue, but I am not sure what you mean by rotating or tilting 360 degrees - and then turning 90 degrees for another 360 rotation. I can't quite picture that. If you are inverting the tank, we should be talking 180 degrees; in other words - turn the tank upside down.
Here's the Ilford instruction: "turn the tank upside down four times during the first 10 seconds and again for 10 seconds (that is, four inversions) at the start of every further minute to agitate the developer. Each time you invert the tank tap it on the bench to dislodge any air bubbles which may have formed on the film." (From http://www.ilfordphoto.com/Webfiles/200629163442455.pdf)
Kodak: "For an invertible tank, one cycle consists of rotating the tank upside down and then back to the upright position. For a noninvertible tank, one cycle consists of sliding the tank back and forth over a 25.4 cm (10-inch) distance. With tanks that have a handle for turning the reel, rotate the reel back and forth gently through about one-half turn at a rate of one cycle per second during the agitation intervals. After the first 30 seconds, agitate for 5 seconds at 30 second intervals. Agitation should consist of 2 to 5 cycles, depending on the contrast you need and the type of tank." From http://www.kodak.com/global/en/profe...bs/j78/j78.pdf
The operative thing here is to invert the tank (if that's possible) and then give it a good bump to dislodge the bubbles. Obviously, there should be room enough in the tank for bubbles.
Note that Ilford recommends 10 seconds once a minute and Kodak, 5 seconds twice a minute. Both come pretty close. The trick here is consistency. It may (or may not) make a difference, but which interval that you prefer is subjective.
Tilt the tank slightly (experiment) while pouring in solutions. They'll go in faster than if the tank is flat on a counter.
Originally Posted by Noble
Seriously, folks, tens of thousands of us have successfully used both steel and plastic reels for decades. The "one is better" or "I can use one but not the other" comes up on this forum frequently. It's usually technique, not equipment.
Yes, turning it upside down is what I mean. Couldn't really define it properly. Sorry for that.
So, talking in Kodak terms: I do two cycles every 30 seconds.
By now I figured out that it's not the equipment that's faulty.
I'll see if I can make a scan of the negatives and post it here soon.
I actually found that the red plastic area in my Patterson tank was leaking when I turned the thing upside-down. So, now, I just use the plastic agitator key to swirl the reel back and forth for 10 seconds per minute. This works great for me!
If the problem is knowing how to get the liquid to swirl, just leave that variable alone and swirl the film instead.
Couple of observations from a 30+ year Patterson tank user. Always start vigorous agitation as soon as the developer is poured in. Most developers froth as you pour them in and you have to get agitation started straight away. I do about 4 inversions in a 10 second period where the tank is turned completely upside down, hold the tank upside down for a second or two to make sure all the developer drains off the film and then turn the tank back right side up. Always tap the tank sharply on the counter after agitation and make sure to "burp" the lid after the solutions are poured in. I never used the twirler as I usually lost them soon after buying a new tank and I don't believe they give enough agitation. If you have ever seen a nitrogen burst developing setup you will never be afraid to give a film too much agitation. I do all my film developing on a jobo now which is continuos agitation.
They all leak if you don't "burp" the lid!
Originally Posted by rwreich