have purchased another tank to roll
I have worked out a clip for the Unicolor Tank...it's not entirely satisfactory, something else will turn up. But have since bought a Jobo with two spirals in it.
Spirals take 6 sheets of 4x5 each, ie twelve sheets per load, and uses just 560ml of chemistry. (The sheets are very tricky to load, so I will still be using the Unicolor drum , and its improvised clip.)
Just this arvo, finished using the new tank with roller (have been waiting on the weather to get some sunny contrast), it was loaded with 4 sheets of 12 year old TMax, one roll of 120 FP4 (also old) and a fresh 135 format FP4, developed in Ilford LC29 at 1+29 concentration. Temperature was 11deg centigrade, and I rolled for 20 minutes. This time included filling tank and time to empty and put in stop, approx 20 seconds each.
The odd mixture of ages and films were exposed with +2, 0, -2 exposures.
The results show that the 0 exposure developed well, and the -2 and +2 exposures are about where they should be. (I was also using old cameras; Graflex 4x5 with Optar lens, Voightlander Vito IIa for 135 format, and trusted shutter and time exposures on my Pentax 645.) So looks like the system, cameras and exposure combinations, and the old film is fairly well calibrated, and can now work out developing times as the weather and water warms up toward summer.
By the way have found old B&W film to be pretty good often. Once used a box of some 30 year old HP5 400iso 4x5 which was still perfect...had been kept in a bedside drawer.
Hey thanks everyone for the help. The rolling drum is the way to go...no more angst and uneven negs, yey!