Not trying to hijack your thread camarillo_cinema... I can remove my post if you wish, just thought I would share my aluminum tube frame here rather then create another thread.
I made a very similar frame, I used 1-1/2" Square Aluminum Tubing for my frame, purchased from my local http://www.metalsupermarkets.com
The cost of my 92"x39" 2.35 frame was $89.00 Cdn after taxes... The store cut my 4 pieces then we both realized that I didn't actually need 39" lengths for my height because I didn't take into consideration the 1-1/2" from the widths so we cut those down to 36" lengths... I'm guessing I could of saved a couple of bucks but we got a laugh out of it anyway.
Metal Supermarket had given me the name of a local aluminum number who I had priced out earlier. He charged me an hour's labor, so $65 and I paid cash.
I picked up my Phifer Sheerweave 4500 from a local supplier in town for $149.00.
I used an sos pad on the frame to rough it up for some primer, primed it, then painted flat black, the two cans of paint were about $8.00 from Canadian Tire.
I then used velcro to attach my screen to the frame, velcro was $40.00 after taxes. I bought 2" loop velcro and had it sewn into the material and then used 1" adhesive velcro on the frame, I wanted the material to have a thicker velcro so I had some overlap with the hook side so I could pull it tight and not worry about not getting good coverage.
All said and done, approximately $350.00 CDN for my frame and I think it looks great. I decided against cross braces to cut down on cost for one and for another did not think they were necessary for only a 92" screen, my screen is rock solid with no bend or bow present, I still have some work to do as you can see by the pictures, I have the screen sitting on a couple of saw horses until I get a chance to build my false wall in its place.Front SideBack SideSide Side ?Close up of Corner