Mine also calls for 1/4" but only from the front spar to
the back spar, since I have flaps. Laminating 2 peices should
be ok but I wouldn't us an 1/8" trowel. I would spred the glue
around with a popsicle stick or scrap wood, quite a few clamps,
and straps of wood to put on top. Clamp one end, then start
clamping every couple of inches until you reach the other end.
Lou