>Original message >wondering if the grain orientation on the 5-ply 1/4" birch ply used on the >firewall needs to be vertical or >horizontal
Ken, Positioning the outer layer grain in the vertical will give you the most strength from the plywood. You want it positioned this way as the most forces will be vertical. An example is from gravity and when you land the engine will exert force downward from it's weight. Mark Jones (N886MJ) Stevens Point, WI E-mail: flyk...@charter.net Web: www.flykr2s.com