A few general comments.
Plexiglass is a trade name for Acrylic. HD has thin acrylic sheets: plastic supply houses will have many sizes and thicknesses, including cut pieces that may be usable for a screen. It's probably the most common material used because it's clear, easily formed, and scratches can be buffed out. But it is fairly brittle, especially at extreme low temps.
Lexan is the GE trade name for Polycarbonate. Polycarbonate has much higher impact resistance than acrylic and better temp resistance. But if it is scratched you cannot buff out the scratches. So it is a great choice for a low screen or a solid color one like the one above, or if you are careful for a taller screen.
The other material that seems to used for windscreens is Polyvinyl Butyrate, also sometimes called just Butyrate. It is clear but feels flexible. I had a BMW windshield on my old R65 I believe was Butyrate.
If you are using the original windshield as a pattern, trace it with paper then make the new sheet a little bigger to allow for the curvature.
When drilling any plastics, the standard angle for a drill bit does not work well and will often crack acrylic. Either start with a timy pilot hole and use a progression of sizes, buy plastic bits, or grind the tip of your drill: you can find recommended angles on the web.
Drill all through holes a little oversize to allow clearance for the screw, as otherwise cold temps may cause cracking.
Sand the edges until they are relatively smooth to prevent cracks. For a clear look, use a solvent to wipe the edge lightly.
Last edited by garandman; 06-11-2007 at 07:23 AM.