Originally Posted by chrisl
I'm a little late to this thread so you may have already figured out a solution. If not here is something you may be interested in trying.
I also have Unicolor drums and have liked them very much. However I recently tried something a little different. In a box of photo stuff I bought cheap was a DevTec 8x10 print drum. This print drum is totally smooth on the inside unlike the Unicolor drum. However it has a feature I really, really like. One end is a "pour in" cap and the other is a "pour out" cap. Why does that matter? Well, the pour in cap has a cup under it. When you tilt the drum to vertical the chemicals inside pour out the "out" cap and you can simultaneously pour your next chemical in the pour in cap. No waiting for the drum to empty. The chems are caught in the cap and don't flow into the drum until you lay it down. I can lift, drain and fill in about five or six seconds. Makes for very accurate timing.
So, I went to the local hobby shop and bought a plastic angle shaped like a "V", a couple of plastic straight pieces like little beams, and a couple of small 1/16" square pieces about 24" long. If you have a Unicolor drum you know where I'm going with this. I glued in the V just like the V in the Unicolor drum. The two straight pieces I glued in at the bottom in position to hold 4x5 sheet film in "portrait" orientation. The little 1/16" square pieces I just glued on the drum wall to allow solutions to reach the back of the film. Only two strips necessary per "side". Finally I glued in a separator in the middle of the drum to keep my film from sliding and overlapping when doing 4 sheets.
This drum will hold four sheets of 4x5 or if you don't glue in the separator you can also do two sheets of 5x7 or one of 8x10. It will work in my Unicolor roller no problem. It is light-tight and a daylight drum. They are cheap even brand new (~$16 at Freestyle under the "Arista" name).