I had gone in on Monday to shoot a screen, but it didn't come out very well, so we washed it out (easy!) and re-shot it, this time with both my images and hers.
Both times the screen was shot we used plain laser printer print-outs saturated with vegetable oil to make them transparent. I think that the images that didn't work weren't good because they were not dark enough. They were text and line drawings that were quite fine, and they came out clear on the screen where I had traced over them in india ink pen, but not where it was just the computer print out. I think they would have worked out better if they had been on a truly transparent ground, or if they had been darker or bolder lines.
The second screen turned out great, Amanda had a river map, a road map and a suburb map, and I had some text from Pablo Neruda's "ode to the atom" and my swan images (the ones from the photo sand blasting tests.)
I had already mixed Reusche "Best Black" high-fire enamel on Monday morning, at a ratio of 2:1 decal medium to powder by weight. This time it was smooth, since I first mixed it with a palette knife, and then with a glass muller for 15 minutes.
We did some test prints with normal printing ink, and after finding that we hadn't completely screwed up the screen, we printed enamel directly onto sheet glass. For each of them the glass was clean, and we flooded the screen before printing. They all went well for a first try at screen printing for both of us, but we could definitely get better detail with more practice.
We also printed the images onto decal paper (which is paper impregnated with gum arabic,) those also worked pretty well.
We also wanted to try to silk screen sandblasting resist. Andy suggested something called "tool dip," normally used to coating the handles of hand tools, but when each of us asked about it in hardware stores, they staff didn't know what we were talking about, so we weren't able to try that, instead we used Weldbond white glue.
Printing glue doesn't work so well, it seems to degrade the photo resist, so the image was not particularly clear. We thought that we might get a thicker layer of glue if we flooded the screen more times, but that just made the image very smudged. We were also going to try silicone caulking, but decided not to since the screen quality was not so great after the white glue, partially since the silicone we had is quite acidic, so we thought it would just make things worse.
Here are pictures of the results from sand blasting the screen printed glue:
I like them, they aren't as detailed as the photo resist, of course, but interesting enough. I'm not sure I'd bother to go to the trouble of screen printing it though, glue is a better resist when it is painted on (it stands up to the sandblaster for longer) and the detail isn't good as we had thought possible.
In the picture above, top left is white powder on black glass, top right is the same, the bottom left is red on white, and the bottom right is red on black.
On Friday afternoon I took everything back into the printing studio to print covercoat on the decals. I'm not even really sure what i did wrong, but the cover coat got everywhere, the coat on the decals was way to thick and ruined the enamels because it made them run. The screen was horrible to clean out, I scrubbed it with mineral spirits for about an hour and the covercoat would come out. Finally, I gave up and pressure washed it out, which worked pretty well.
So, I'll be firing these on on Sunday during my blow slot, hopefully they work out... I'm not so sure about silk screening, mostly, the results I've gotten so far aren't what I had hoped.
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