Not sure about your thinking for the scrog but something that work very well is to construct the frame out of 1/2 or 3/4 inch PVC piping and elbows. You can see an overly complicated version here:

http://boards.cannabis.com/hydroponi...ml#post1743543

All you need are four elbows, some piping and the screen (2" x 3" suggested) and some zip ties to secure the screen. Don't bother with pipe glue. There's no need and moving it at a future date will be easier.