There's a couple ways you can set the windows for use with Permadri.
There's the butyl rubber method that badoleross I believe used. I can't really say yay or nay on it since I haven't done it, but he had success with it.
Then there's what I'd suggest. Use Dow 795 to set your window BEFORE you coat the tank. After your window is set, run a bead around the window with Dow 795 then mask off your window. Dow 795 bonds well to glass/acrylic and wood. Permadri WILL bond to cured Dow 795 even though Dow 795 and other silicone products won't bond to Permadri. Leave about a 1/2" - 1" border of your window unmasked and coat over it with Permadri. You should have at least 1" of overlap from your frame anyway, so this won't be seen. Apply all your coats of Permadri until it is 60 mils thick, then unmask the window. Voila!
There's the butyl rubber method that badoleross I believe used. I can't really say yay or nay on it since I haven't done it, but he had success with it.
Then there's what I'd suggest. Use Dow 795 to set your window BEFORE you coat the tank. After your window is set, run a bead around the window with Dow 795 then mask off your window. Dow 795 bonds well to glass/acrylic and wood. Permadri WILL bond to cured Dow 795 even though Dow 795 and other silicone products won't bond to Permadri. Leave about a 1/2" - 1" border of your window unmasked and coat over it with Permadri. You should have at least 1" of overlap from your frame anyway, so this won't be seen. Apply all your coats of Permadri until it is 60 mils thick, then unmask the window. Voila!
