[lizs216]

Hello all! I need help!

I'm relatively new to screen printing and am still trying to find an emulsion that is a good fit for my pretty basic, at-home setup. I've recently decided to try Ulano 925WR.

After I first mixed it, I did a step test on a 18x20 160 mesh screen. My step times went from 70-120 minutes. The artwork test washed out fine throughout the whole screen, but I stopped seeing color change at about 105 minutes. I then went to my 20x24 156 mesh screen and have had nothing but trouble. I have been unable to get the emulsion to wash out after exposing. I have tried several more tests, each time not getting a clean washout. I thought it might be overexposing, so I've done tests at times as low as 40 minutes, but am still getting very poor results.

My exposure setup is single task lamp with 150w bulb, glass, artwork, screen, black felt, board. I realize I might need a second task lamp for the bigger screen (this is my first try at the larger screen), but would that be causing all the trouble? Or is something else amiss?

Thanks so much for any help!

 

[selanac]

You need a shop light 500 watt bulb. They're about $12 at home depot. Expose 12 inches away, for 3 minutes 156 mesh.

 

[lizs216]

Do you think I could be having contact problems? And the shorter exposure from the halogen would negate them?

 

[selanac]

It's hard to tell when you're using a light bulb and we don't know what your artwork looks like.

If you have a lot of detail and/or too close together you'd have to use a high mesh. Also, how thick is the glass? Is it Non-UV.

If you buy a shop light, remove the glass over the bulb. It's UV protected, and you need UV to expose screens.

https://www.youtube.com/watch?v=1OIpRQt9ttY