GREAT PLANES Rapture 40 Instruction Manual page 12

7. Use medium CA or epoxy to glue the die-cut 1/8"
[3.2mm] plywood R2A rib doublers to the correct side of
three die-cut 3/32" [2.4mm] balsa R2 ribs as shown in the
photo for the wing panel you are working on.
8. Use a straightedge and a hobby knife to cut partway
through the outside of rib R1 between the spar notches
as shown.
9. Using a small square to keep the ribs vertical, glue
all the ribs except ribs R1 to the bottom spar. Also be
certain the ribs are contacting the wing jig as you go.
10. Glue the top spar to the ribs, again making sure
the ribs remain vertical. Don't forget to position the top spar
to cancel out any warp that may have been in the bottom
spar. If any of the ribs lift from the wing jig, use T-pins to hold
them down.
11. Glue the die-cut 1/8" [3.2mm] plywood forward
and aft dowel plates into position. Note the angle on one
end of the dowel plates. This is the end that goes on R1.
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