Great Planes PT-40 MkII Kit - GPMA0118 - Manual (Page 33)

plywood washout jigs directly under each tip rib – the jigs
should stand vertically. Be certain the jigs are positioned
correctly as noted in the photo at step 8. Hint: It helps if
you can pin the TE and rear center rib to the work bench.
This will keep the wing from sliding from side to side while
you position the washout jigs.
❏
10. Tack glue the jigs to the LE, bottom main spar and
TE of each wing tip with a drop of medium CA.
❏
11. Press the bottom sheeting to the bottom of the ribs
and the bottom forward spar, simultaneously pulling it tight
to the leading edge. Use thin CA to securely glue the
sheeting only to the ribs and the bottom forward spar. Do
this one section at a time, working from the tip to the root of
each wing panel.
Refrain from using any accelerator during
this and the next step. Remember, residual accelerator can
prematurely activate the CA you will apply during the
following steps (Photo is shown with the tip jig removed
for clarity).
❏
12. Glue the bottom sheeting of both wing panels to the
LE with medium CA.
❏
13. If necessary, lightly sand the tops of the wing ribs to
even them up. Make sure there are no glue bumps or
imperfections that will prevent the top sheeting from fitting well.
❏ ❏
14. Use the same “mark and trim” technique we
showed you for the bottom sheets to cut another 3" x 30"
sheet for the top of one of the wing halves – remember to
cut it slightly oversize at first. The top sheet fits between the
LE and the main spar. Sand a slight bevel along the leading
edge of the sheet, then test fit it between the LE and the
top spar. Trim the root end of the sheet to fit evenly on the
centerline of the 1-A rib.
❏ ❏
15. Hold the sheet tightly against the LE, then wick
thin CA into the joint along its full length. Wipe off any
excess CA before it cures.
❏ ❏
16. From the rear of the wing, gently lift up on the
sheeting. Then, working quickly, apply a bead of medium
CA to the top of each rib and the top forward spar. Press
the sheet into position and hold it there, applying even
pressure or using T-pins to hold the sheeting until the CA
cures.
❏
17. Cut and fit the sheeting for the LE of the other wing
panel. Try for a nice joint at the center by careful sanding
and test fitting. Fit and glue the second sheet in position the
same as the first sheet.
Use a ballpoint pen and a drafting triangle or a building
square to
accurately mark one of the remaining 3/32" x
3" x 30" sheets, dividing it into four 2-3/4" wide sheets
and four 4-3/4" wide sheets. Use the square to keep the
ends of the sheets perpendicular to the edges. Cut the
sheets into sections along the lines you marked with a
hobby knife and a straightedge. The 2-3/4" sheets are
used to sheet the
top of the wing tips and the 4-3/4"
sheets are used to sheet the top of the center section.
33
THIS STEP FOR PT-40 MK II ONLY
Sand a slight bevel on
Leading Edge