I use Ulano Proclaim (extremly long exposure latitude). I coat the mesh 120T and 100 T. I dry the screen for 90 min at 40 C (104F) and then I expose it on a 750w halogen lamp. The distance from the lamp to the screen is 30 inches and the time of exposure is 8 minutes. Dimensions of the screen are 12 inches x 40 inches.
After exposure my coated screen is partially washed off. what is the necessary exposure time? Any advice? Thank you.
You need to do a step test or get an exposure calculator. Best 30 bucks or so you can send when dialing emulsions. When using diy style light sources you'll will have a difficult time finding reliable times and distances online and even if you find one you'll still have to dial it in on your own, since there are so many variables that can effect exposure time. If you get an exposure calculator you will avoid many headaches.