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.
Last edited by ohdanielsan; 08-26-2008 at 05:41 PM.
will do, and you're right - washout sucks now, and reclaiming is like pulling teeth - not to mention the horrible stain it has been leaving on my screen.
i really do like the performance of the 8000 when i'm not taking stupidly-long breaks from my studio. i actually started using it only because it's what they were using in my screen printing class. of course they were using a professional exposure unit that burned screens in 55 seconds flat. so needless to say, my rickety halogen setup is worlds apart from that. i was thinking maybe another emulsion might be more sensitive and appropriate for my ghetto-rig, but 12 minutes isn't too bad as long as it stays that way while the emulsion is good.
@squeegeethree: I dug it too before I let it die, but now I'm thinking I might give something else a try just for the learning experience, and then come back to 8000 when I have a more "pro" set up with better UV exposure.
@Adrocket: Yeah, I've heard QTX can even keep up to a year and a half if stored properly. The one thing I've heard against it though, is that when used with WB ink, it somehow gets harder to reclaim...? Is this true? That's the only reason I am hesitant to give it a try. I have a pretty strong powerwasher though, so maybe not a concern for me?
@Andy: Which Murakami do you use, the Photocure Pro? They sound magical from all the stuff I've read around here (or maybe I'm just reading your posts too much ). Just out of curiosity, where do you order it from? I don't think my local dealer carries their stuff. I'd probably have to find it online.