I am working on a 20x24 UV exposure unit for my screen printing efforts. I have most of the parts, but I am looking for a local source for glass. Know of a good place to get a 20x24x1/4" glass plate in Minneapolis/suburbs?

Would 2 sandwiched sheets of 1/8" glass from picture frames work?

I may have a couple sheets of Tempered 1/4 inch glass that is close to 20" wide, and maybe 36 inches long.. I will have to dig that out and check

Unfortunately no. There will be some weight put on it.

Here is a link to something similar to what I am building. This ones pretty large, I only need 24x26 of surface.

http://www.gigposters.com/forums/screen ... tubes.html

Another trick I heard about uses a 2 gallon ziplock with some sand in it to create even downward pressure across the entire screen. This is to keep the screen and artwork squished flat to the glass. That the reason I am looking for 1/4 inch thick glass. Plus it cant have UV coating on it, so that counts out tempered storm windows

i've got a source in ny for you, but there's gotta be someone local. give gaytee a call, i doubt they have it but they're my go to place for weird glass questions.

I measured just checked the glass in my garage, it is close to 20 inches wide, and much taller.

While it is tempered, it was for a shelf, not a window, so would they have used UV coating on it?

I will try and remember to toss it in the truck for Wednesday or Thursday.

it may very well work, thanks.
I have an exposure area of 17.5", but need some room to make a lip for the glass to sit on.

I'm curious about the whole UV thing. I was under the impression that glass in general blocks UV- I seem to recall a (possibly apocryphal) story about Richard Feynman watching the Trinity test through a truck windshield- thus being the only person NOT wearing a welding mask at the time.

Perhaps even in 1945, car windows were treated to screen UV?

yep all glass filters some UV, usually below 320 nanometers. Standard glass with very low lead content (320-700) work reasonably well at transmitting UV. Though of course some is absorbed. Some plastics (plexi) are better, but then most of the stuff you find for window replacement has uv blocker added to it.