Bear in mind that the timer really can't be used to turn on or off a metal halide light of the warehouse light type. One reason I went with a multiple-tube unfiltered blacklight rig with a pond-liner vacuum blanket instead of a home-spun metal halide one was the convenience of using a timer so I didn't have to babysit the unit. A fluorescent tube job with a vacuum blanket will do very good screens. I've still got 2 that I made. I've since sprung for a commercial metal halide unit and it is far and away one of the best investments, next to my current press, that I've made, but it wasn't cheap.Hi Tom,
Looks like you and I frequent the same forums. Thanks for your response on Screen Printer Open. I will look into a darkroom timer.