Wanting to obtain the best possible consistency with my 8X10 work I am trying drum developing. I started with a Beseler drum and a Unicolor base(the kind that reverses automatically) but the smooth walls on the Beseler drum were not helping so I aquired a Unicolor print drum and began testing it out. It is an 11X14 drum so as I can do 2 8/10's at once. The problem I am experiencing is driving me nuts! I keep getting lines where the ridges are on the inside of the drum. The lines are about 1/4 inch wide and run the length of the negative. They aren't showing with every single ridge on the drum but they will be in like a group of three(spaced the exact distance as the ridges) then an inch or so with none, then a group of maybe two, then none for awhile, then maybe a group of four, etc., etc. Also the lines aren't all exactly 1/4 inch wide as they deviate(not like they were drawn with a ruler). I am doing the testing with FP4 and Pyrocat 2:2:100 using 500ml chemistry for two sheets. And yes the emulsion is facing in towards the center of the tube. My thought at first was that the weight of 500ml of chemistry is causing the film to sag or scallop between certain ridges and thus setting up a non desireable flow pattern resulting in an uneven type development but I originally started out with 200ml chemistry and not only had the vertical lines but uneven densities running across them. When I upped the chemistry to 500ml the uneven densities went away. I have even tried presoaking out of the tube and loading wet to no avail. I know people use these and love them but I am so perplexed by what is happening. Especially when I hear "Never had a problem", "Never once had any streaks", etc., etc.
Here is my procedure (in the tank**);
1) Pre soak in distilled water for 5 min.(In the drum and running)
2) Pyrocat 2:2:100 for 7 min.
3) 15ml 28% acetic acid/1000ml water for 1 min.
4) Kodak F4 fixer for 4 min.
**using 500ml chemistry
Out of tank;
5) HCA 1:4 for 2 min.
6) 20 min. wash
7) 1 min photo flow
8) 20 min wash.
Actually the steps 5-8 are meanningless as I see the streaks as the film comes out of the tube and before I put it in the HCA.
I have run about 8 sheets so far and some are not as bad as others but they are there on every one. I was using a citric acid stop bath on a few and it was the same. I actuallu aquired TWO tubes and the other one does the same thing. Any help would be really appreciated. I have searched usage of unicolor print tubes and haven't seen this before on other posts. Thank you kindly in advance for your thoughts and time.
I use the same set up but only process one sheet at a time and have not had the problem you are experiencing. What I load the film in the tank do you make sure it is trapped behind the ridges and prevents the film sheet from movng?
I have not used Pyrocat in this setup but have used HC110, D76 (1:1) and XTOL with good even results. My procedure is very similar to yours.
I really have no clue as to the problem. In my own work I have never used a 11X14 drum for processing 8X10 film, but I have used one of the same diameter and with the same internal configuration to develop two sheets of 7X17 at a time.
As far as I can determine your procedures are virtually identical to mine.
Are the streak lines on the outside of the film (facing the drum) or on the emulsion side (facing in)? The question assumes that you loaded the film correctly. However, given your description of the process the only possibility that enters my mind is that you loaded the film incorrectly, with the emulsion side facing the wall of the tube. If you were to do this it would certainly result in the patterns that you descriibe. Otherwise I have no way to explain the streaks.
Could it be the Anti-halation layer sticking to the ridges and leaving streaks? When I use my homemade BTZS tubes, I have to remove the film and fix in a tray. If I don't I get streaks from the flim backs resting on the inside of the tubes.
I also have the 8X10 Unicolor tube. I can see the ridges running length wise. They would be touching the film base, not the emulsion.
Just a thought...
I didn't include this in my original question but I will at this time:
The film is defenitly loaded with the emulsion towards the inside of the tube(I have done some really stupid stuff in the past so yes I never ruled that out)!
I did in fact on several sheets fix for two minutes in the tube and then two minutes outside the tube.
I did do a side to side agitation OFF the base at one minute intervals.
All these things considered I am befuddled! Thinking at great length on these I was wondering if there is a chemical contamination issue here? Could the old plastic be somewhat porus and holding a chemical that is tainting my chemistry and or film? I washed the insides with a citric type cleaner and even left them with water in overnight standing up on end. Maybe I need to try to use something to neutralize the inside of the drum? Vinegar? Any thoughts would be welcomed wholeheartedly.