Ok so here is exactly what we have used-
http://nwgraphic.com/family.php?id=LS-850&dd=LIQUID-SEAL&cat=liquid-sealI'm sure there are others you can use. Hard part for us at the start was applying it thin enough that it did not drip, yet still having enough of it to still cover. We just apply it with a 2" plastic $0.32 putty knife. It is extremely(yet tricky) helpful if you can have a vice hold one end of the screen and then you can run the putty knife on the top and bottom of the screen at the same time, 3 sides on all screens then flip them and do the remaining side. The stuff I posted is clear-ish so we actually put a few drops of WB/DC pigment in it so it stands out a bit better. Getting a
SMOOTH coating is
KEY bumps(drips) make coating a pain.
The original place I knew of in the states that did this process was in MI somewhere, their name is something like CGS, GSC, GSK, GCS(you guys get the idea). They do a nice job! They also swear the calk they use in the corners is as heavily protected as the Coca-Cola recipe. I have found that a basic construction adhesive works well. We do prep the area with the same abrasive tool we use to prep the screens before we stretch them. That gives the adhesive "grooves" to adhere to.
For all I know, we do it completely backasswords and everyone has a much better way but that's how we have done it!