Mine is 3 inch wide aluminum similar to Larry's and covers a gap of at least 2
inches wide. It has a screw about every 24 inches and that holds it down
pretty good. Previous owner "snuck" the plane up into the air with no adverse
effects. The real trick is to start at one end with the fasteners, and drill
then mount. Otherwise the holes might not line up later. Also use a rounded
head screw unless you have counter sunk the aluminum, or the flathead screws
will stand up more than round heads (don't ask how I know).
Colin & Bev Rainey
KR2(td) N96TA
Sanford, FL
crain...@cfl.rr.com
http://kr-builder.org/Colin/index.html