Several years ago I saw a web posting and used that to design my own drying cabinet; it's Version 1, and when I get some time I'll build a larger Version 2.
My cabinet is made of pine boards, about 4' high and 1' square. The top has a shelf with 1" holes bored through it and a filter sponge (about 1/4" thick) sits on top of that. The bottom shelf has a large hole and I fit a large diameter (5"), low velocity fan. I took the socket, cord, and switch from a dead computer power supply and mounted the outlet and switch on the side at the bottom. The inside and outside are painted white using an enamel for a shiny finish. This makes it easy to keep clean.
Toward the top I drilled shallow holes on both sides and put in 1/8" aluminum rods. I hang 120 roll film, 35mm roll film, and sheet film from these rods.
The front door has thin foam weather stripping where it meets the top, bottom, and sides. Two latches hold the door snugly closed. When loaded with film, the air is drawn in through the foam filter on the top and exhausted through the fan at the bottom. I've had no watermarks on any film. No heat is needed. I let the film sit there a few hours and it's dry with hardened emulsion.
Having used it a few years, the next version will be taller, wider, and deeper (to better accommodate the 4x5 and 5x7 sheet films). I'll use the same fan, socket, switch, and cord and build it the same way. It's worked perfectly and was a lot less expensive compared to the commercial versions.
Rich
