hey dudes and gals, this is my first post, so hello-hello to everyone
i've been putting together a backyard screen printing studio and have a homemade exposure unit (1500w halogen light). at the time i put it together, i tested out exposure times with a step-wedge and got about 12 minutes. unfortunately, i had to abandon the studio for a while because of my day job, but i'm finally back 8 months later. nothing has changed about my setup, but the problem is, my exposure time of 12 minutes is totally gone, and not even a 70 minute exposure will cure the emulsion now (i use Autosol 8000). i immediately thought that the emulsion had simply gone bad. admittedly i didn't store it properly all these months, and i live in LA where it can easily get around 90-100 degrees in my studio.
however, here's where it gets weird: as a last test i exposed a screen in the sun, and to my surprise i got a 2-3 minute exposure! i realize that halogen lights don't provide the best source of UV light, but it DID work 8 months ago with my light. could it be that the emulsion has lost its sensitivity enough to stop working with halogen, but still work in the sun?
i know i could just buy new emulsion as an absolute test, but i thought i'd check with you guys first before spending anymore unnecessary cash.
also, if you guys know of a better emulsion for a halogen light source (quicker curing, good with water-based flatstock printing...), i'd love to hear about it. as i said, i'm using Autosol 8000, but i'm not married to it at all. i was thinking maybe Ulano 925wr would be my next try, based on things i've read around here. any thoughts?
thanks for any help you can throw my way.