On Tue, 23 Mar 2004 21:39:06 GMT, Ernie Leimkuhler
wrote:

A fine mesh expanded metal painted black.
It should block a lot of light, but still allow air to pass through.
It would be lighter than wood and pretty strong.

http://www.mcnichols.com/products/ex...lat/index.html

A perfect option would be V-louvers, but that would be very costly.

V-louvers are inverted V's stacked a little bit apart.
Air pases right through, but light is blocked.

A little experience with satellite dishs - the perforated models
appear solid, but seem to have nearly the wind resistance of solid as
well. The mesh ones let a lot more air through, but you can see
through easily, or at least up close you can. Gate openers- there are
some beefy ones for sure. Our Big Ugly Dish (perf) has taken some
brutal winds, motor chain-drives a worm gear. Two of the solar
trackers use the exact same mechanism, and those arrays are really
heavy. Only about five feet of leverage on them though. Wouldn't be
surprised if some of the ground-mounted gate openers use the same
scheme. As to the screw-type openers, had a cheapie one once. About
18" of screw travel to move a 12 ft. gate through 100 degrees. A lot
of stress on that thing, especially at the mount. Mechanism proved
tough enough for a light gate, but the mount was a headache. Who
woulda' guessed it, lag screws into a wood post. :-) Very sloppy
where even a little loosness made for too much travel on the gate. A
welded arrangement would have been a huge improvement. An adjustable
pivot would be smart since the geometry has to be just right.

Wayne