Scarfing plywood is very easy if you have access to a portable 3 inch
electric plane. Decide on the angle, generally 8 or 10 to 1, which would
be 1or 1 1/4 inches for eighth inch stock. Mark the 1 inch line on the face
of one piece, provide good, straight support under the edge and go to work
with the plane. You can easily control the angle by looking at the plywood
laminations. By keeping the laminations equal width and the plywood joint
lines straight, you will make a nice flat surface for gluing. Do the same
thing for the mating piece and glue with epoxy. This usually means painting
epoxy on both surfaces and following with thickened epoxy. Align the
sheets, and you have it. Judicious use of polyethylene sheeting will
prevent gluing the long sheet to the workbench. Some people use tacks to
hold the pieces in position. It is a good idea since two pieces of wood
slathered in epoxy love to move around before the epoxy sets. Good luck.
Doing a trial run is recommended.