[lbridenstine]

I'll start off by saying that I've only screen printed one or two things before and that was 10 years ago in my graphics class, freshman year of high school. I recently decided to start screen printing with a friend for ourselves and local bands and designers. We will be doing mostly black t-shirts and patches with white ink (Jacquard water based), but will occasionally do other color shirts and ink. I've done a good deal of research on what to get and how to set it up, but I'm having an issue.

Here's what I have:
-20x24" 156 white mesh wood screens
-Ulano QX1 emulsion coated with a 14" squeegee for now, one coat on each side, semi-thin layers
-Fixxons inkjet printable waterproof film positive
-Epson R380 photo printer set for premium photo paper glossy (any ideas for better print settings?)
-18x24" clear acrylic (which I just looked up and found out that it's UV treated)
-1.5" black foam
-500w halogen work light (glass and cage removed)
-Turned my "music/recording room" in the basement into a darkroom with black foam covering the window and yellow light-safe bulbs

I made a sheet with times from 16-20 minutes in increments of 15 seconds, because I saw on a couple different threads that people were saying 16-18 minutes worked for them with this set up. I don't have an exposure test strip, as you may have guessed. I made 3 sets of numbers (all on the same sheet), one opaque with diffused edges, one half tone, and one with fine lines to try to test the detail during exposure. The ink was pretty opaque, but not as opaque as it was when I accidently printed on the wrong side of the sheet (the ink ended up bubbling up, then it wiped off clean with a paper towel).

I degreased the screen, let it dry, coated the emulsion, let it dry with the shirt side down overnight, got up the next morning, taped the film onto the screen right side down with scotch tape, taped the acrylic sheet over the screen, put the foam wedge inside the screen. I couldn't think of a good way to have the worklight above the screen, so I put the screen/foam/acrylic on a guitar stand and sat it up as straight as I could and put the work light on a drum throne with the height being in the middle of the screen, 26.5" away from the screen. I covered each number as that time passed and turned the light off when it got to 20 minutes.

Then I took the screen to the bathtub and rinsed it with the shower head with fairly low pressure, let it soak for a couple minutes, then sprayed it closer with the same pressure for a few minutes and the numbers started to clear, but the emulsion around them began peeling, then by the time most of the numbers were clear, it was peeling and bubbling all over the screen and the squeegee side of the emulsion pretty much rinsed out.

After that happened, I figured I should just reclaim the screen and the majority of it came out with just water. I only had to use emulsion remover to get the last bits of it.

So, I'm looking for some advice. My first thought was I need to expose it for longer, but then I found out the acrylic sheet was UV treated and I'm wondering if that could be the problem. Does anyone know if plexiglass from a poster frame would work better? Does it make a difference that I had the screen and light upright instead of laying flat?

The emulsion was torquoise after exposure and I think I've read that it should be green, but being the first time I tried it, I wasn't sure if that was as green as it would get, so I tried it.

Also, when I took the film positive off after exposing, parts of the film stuck to the emulsion and a layer of the sheet peeled off and stayed on the emulsion, so the film can't be reused. Does anyone know why this happened or how to stop this from happening?

I'm hoping to find some helpful advice before I waste more film positive, emulsion, and time. Any help is appreciated!

Thanks!

 

[ScreenFoo]

So, I'm looking for some advice. My first thought was I need to expose it for longer, but then I found out the acrylic sheet was UV treated and I'm wondering if that could be the problem.

The emulsion was torquoise after exposure and I think I've read that it should be green, but being the first time I tried it, I wasn't sure if that was as green as it would get, so I tried it.

Also, when I took the film positive off after exposing, parts of the film stuck to the emulsion and a layer of the sheet peeled off and stayed on the emulsion, so the film can't be reused. Does anyone know why this happened or how to stop this from happening?

I'm hoping to find some helpful advice before I waste more film positive, emulsion, and time. Any help is appreciated!

Thanks!

The plexiglass isn't going to work out well for this. As for the poster frame, it may be better, but crappy glass can be had for free so often, it doesn't make too much sense to me.

A diazo emulsion will turn from green to blue on white mesh--if it's still turquoise (blue--green), that's a sign you're underexposing.

If the film sticks, you may not have dried the emulsion well enough, or the film well enough. Perhaps it's humid where you're at?

An exposure calculator and a scoop coater will pay for themselves within a few buckets of emulsions time.

 

[lbridenstine]

The plexiglass isn't going to work out well for this. As for the poster frame, it may be better, but crappy glass can be had for free so often, it doesn't make too much sense to me.

A diazo emulsion will turn from green to blue on white mesh--if it's still turquoise (blue--green), that's a sign you're underexposing.

If the film sticks, you may not have dried the emulsion well enough, or the film well enough. Perhaps it's humid where you're at?

An exposure calculator and a scoop coater will pay for themselves within a few buckets of emulsions time.

Thanks for the reply. I just asked about the poster frame glass because I have a lot of poster frames at my house and no actual glass sitting around. Can I just use spray adhesive and take the glass/plexiglass out of the picture?

The emulsion doesn't have diazo in it, it's SBQ dual cure, but I assume it's the same concept with the color change?

Yeah, I did put the film on right after I printed it, so maybe the ink hadn't dried yet. I'll let it sit for a little bit next time. I don't think humidity is a factor. I'm in MI and winter usually brings really dry air. Although, I'll probably end up with that problem before summer.

I know. I'm just trying to save a little money where I can. I will get a scoop coater eventually I'm sure, but I don't know how much I'm actually going to be printing yet and figured I could use a squeegee until I find out. The exposure calculators I've found have been $30+ and I figured I could try making my own for just the cost of a sheet of film positive and see if it works before buying one.

 

[ScreenFoo]

If you've got spray tack, sure, you can spray tack your positives and stick them right on the screen--I think the mist works a little better than the web if you have both. It isn't perfect, but it works well if you line up an edge on center first, and burnish it down.

A Stouffer strip can be had in the 10-15$ range--if you're using an SBQ, it's almost a necessity. The exposure latitude on these emulsions is very narrow, compared to diazo and dual cure formulas. There is no color change until you start rinsing, and even then it's very slight.

And don't get me wrong--if you can learn how to coat well with a squeegee, you'll be pretty handy with a squeegee--not a bad thing.
The problem is, if you decide to switch to a scoopcoater, all the work you did before figuring out times--you will then have to redo.

 

[lbridenstine]

If you've got spray tack, sure, you can spray tack your positives and stick them right on the screen--I think the mist works a little better than the web if you have both. It isn't perfect, but it works well if you line up an edge on center first, and burnish it down.

A Stouffer strip can be had in the 10-15$ range--if you're using an SBQ, it's almost a necessity. The exposure latitude on these emulsions is very narrow, compared to diazo and dual cure formulas. There is no color change until you start rinsing, and even then it's very slight.

And don't get me wrong--if you can learn how to coat well with a squeegee, you'll be pretty handy with a squeegee--not a bad thing.
The problem is, if you decide to switch to a scoopcoater, all the work you did before figuring out times--you will then have to redo.

I'm not sure what mist vs. web is for adhesive, but I would think I have a mist one? I'm pretty sure what I have is Elmer's Craft Bond and it says if you spray it and let it sit for a few minutes it will make a temporary hold instead of permanent, so I'll try that next time.

I'm kind of confused about SBQ vs. Dual Cure, because the emulsion I got says

"QX-1 is an SBQ sensitized, hybrid dual-cure emulsion that combines the convenience and shelf life of SBQ with the durability, versatility, and imaging properties of dual-cure emulsion.

QX-1 is compatible with all plastisol, UV, and solvent-based ink systems. Its matte finish virtually eliminates printing problems associated with high and low humidity conditions. QX-1 is formulated to provide wide exposure latitude and is easily reclaimed even if underexposed and used with aggressive inks and washup solvents."

Also, when I ordered this, I asked the company (screenprintingsuperstore.com) if this would work with water based inks and they said yes, but it doesn't say it on Ulano's website, so I hope they were right.

 

[ScreenFoo]

It's wider than many SBQ and photopolymers, I should have clarified-- a diazo, or diazo dual-cure. Not sure what qualifies as a pure photopolymer dual cure--two photopolymer sensitizers, I would assume, but don't quote me.

They do list it as compatible with water base ink systems, you should be OK there.

If the spray tack mists, it's a mist adhesive--if it webs (little strings) it's a web adhesive. Sounds like you probably have a mist, most craft store spray adhesives are.

 

[lbridenstine]

It's wider than many SBQ and photopolymers, I should have clarified-- a diazo, or diazo dual-cure. Not sure what qualifies as a pure photopolymer dual cure--two photopolymer sensitizers, I would assume, but don't quote me.

They do list it as compatible with water base ink systems, you should be OK there.

If the spray tack mists, it's a mist adhesive--if it webs (little strings) it's a web adhesive. Sounds like you probably have a mist, most craft store spray adhesives are.

Alright, good. Thank you. I'll try it without the plexiglass, with spray tack, and if my second attempt with the homemade exposure test doesn't work, I'll buy one. I'm hoping I have the right time frame that I should be working with in the 16-20 range. Other people were saying 18 minutes for this emulsion with a 500w work light and 156 mesh, but I don't know what their distance from the screen was.

 

[lbridenstine]

Oh yeah, any thought on printer settings for fixxon film positives? I have an Epson Artisan 710 and an Epson R380, neither one says they can print on transparencies, but the R380 worked, while the 710 just pulled it through and didn't print on it. I put it in grayscale and chose "premium photo paper glossy", chose "photo RPM" and unchecked "fast speed" or something like that. It was pretty opaque, but I don't know if it was opaque enough.

I'm printing it from Corel Painter X if that matters at all as far as what settings it has. I don't have any other software that would work better for design unfortunately.

 

[lbridenstine]

Alright, I tried it again and I did a pretty bad job at coating the screens apparently, they looked alright, but while they were drying, the emulsion started bubbling up and dripping off. I'm assuming I put too much. I tried to smooth it a bit, but it was already half dry (you can see the circles in the pictures). I tried exposing it anyway after it finished drying, just to try it. I did a 156 screen and a 220 screen.

I used that exposure calculator that someone posted in a different thread. It turned out better this time, but as you can tell by the photos, still not good at all. The 220 screen (right picture) had better results than the 156 (left).

I just ordered a scoop coater, so I'll use that next time and hope that it will solve some issues. The film positive still stuck to the emulsion even after printing it a day ahead of time, maybe a thinner coat of emulsion will be better with that too?

 

[TYGERON]

Screen Printing 101 DVD | eBay

And there's a "Buy It Now" one listed for $49.95

Another forum member recently posted that she purchased this and did exactly what they said and she had none of the common problems posted on the forum.

 

[speshoot]

i know this is a late reply but i hav ALMOST same problem with QX-1, did u ever find a solution?