I love TZ, have used it for about 50 posters so far and it's been pretty reliable/flexible.
But lately I've been having an issue. After exposing I wash out the screen, everything looks real good. But when I look at the mesh after it's dry, there seems to be a fine glaze or residue that's dried in the open part of the stencils. Like some streakyness from the emulsion seeps down into the open areas and partially blocks the stencils when I go to print. It's also been troublesome when I go to reclaim the screen, causing me to need to replace mesh prematurely.
The emulsion is pretty fresh, about 3 weeks old. I tried letting the screen dry flat but that doesn't seem to help. I'm using a 500w halogen utility lamp. I typically expose for 19 minutes. More time? Less?
I had the same problem. What are you using for washout? If you are using substantial water pressure, it can create this sudzy glaze that can be trouble. Try keeping a cup or two of hot water around, and pour that down each side of the screen after you're done washing out. Should do the trick.
for reclaiming the screen I'm using #4 blue. I don't have a power washer because I print my apartment (yeah, I know I should use a power washer); my main concern is where I wash the screen after exposing. A cup or two of hot water, hmm. Thanks.
I had the same problem for awhile as well.. usually would happen once the emulsion started to go bad. I was using speedball diazo emulsion at the time (which is bad emulsion to begin with). Now I use ProChem DXP Pink (from Ryonet) and have never had the issue again.
Do you keep your emulsion refrigerated or at least in a cool place?
After you rinse out the screen try blotting it with newspaper or somew type of paper that will absorb most of the water. If I rinse my screens and just let them dry I get water haze. I just do this so I don't have to mess with the screen.
Probably not.. at least not the way it's being described. Of course I can only speak for my situation.. but the residue would only show-up after the burn and wash out not before coating the screen. I really think it's cuz the emulsion has turned.
Originally Posted by strawberryluna
couldn't this also be from repeated, only partially-removed emulsion building up residue from not using a power-washer on the reclaim?
I always keep my emulsion in the fridge, it's only 3 weeks old. I've previously been able to use Ulano TZ for several months no problem. Yeah, I'll probably do as the others suggested and give it a few more minutes under the lamp and then blot the screen with paper towels or newspapers.
"couldn't this also be from repeated, only partially-removed emulsion building up residue from not using a power-washer on the reclaim?"
Actually, I've been having the same thought... maybe I should bite the bullet and put a power-washer in my little apartment bathroom.
Also, Luna, thanks for the tip on Cougar paper. I've been having curling issues with Springhill Tag. Does Xpedx distribute Cougar?