Originally Posted by BungalowFilms
The screen members would wind up being 1 inch thick by 3 1/2 inches wide and would be laminated together out of five layers of 1/4 inch thick Luann plywood. Like most plywood, Luann is slightly undersize in thickness; the five layers stacked up measured almost exactly one inch. Luann is an inexpensive imported mahogany plywood. In hindsight, it might have been better to use a better quality material (less flex) but at the time, the Luann was all I could find in a ten-foot long sheet.
I'm so glad somebody revived this thread ! It is not one I ever found when searching for curved screen builds. Laminating plywood strips had occurred to me as the best way to arrive at stiff and straight long frame members -- more so than trying to find 12' lengths of straight poplar or other woods -- and for much lower cost. I'm happy to see somebody else has already proven the concept. Luann would be even cheaper than the 1/4" sanded ply I'd also considered.
You mention that 5 layers still ended up flexible, and I'd like to know just how flexible, because flexible is what I actually desire. I am planning on a screen anchored to the wall only at the midpoint top and bottom, such that the sides can be pulled out from the wall and held there by legs/flaps to form the appropriate curve for when my a-lens is in place. I need to find the right level of stiffness so the curve created by just holding the sides out is smooth. Then those legs/flaps will both pin the screen sides flat against the wall and be the side masking for 16:9 when the a-lens is not in place. I had thought any more than 3 layers of laminated Luann would make it too stiff to perform this bending and flattening, but you say 5 layers was still so flexible that you needed support ribs ?
Also, you mentioned you used Luann because it came in 10' lengths, but I didn't think full length would matter in a lamination. Being able to buy just two sheets of 4x8 Luann and build up 12' long top and bottom members
via laminating 6" wide strips of offset pieces seems workable, no ? 8' lengths will fit in my SUV if HomeDepot will rip them down to 2'x8' for me.