Join The Wing Halves; Fiberglass Center Joint - GREAT PLANES ElectroStreak Instruction Manual

JOIN THE WING HALVES

1. Glue* the die-cut 3/16" balsa center rib to rib W-
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1 of the left wing panel. (This center rib is slightly oversize
to allow for positioning). Then sand the center rib even with
the left wing panel.
*A thin layer of 5-minute epoxy or aliphatic resin glue is
recommended, to allow time for positioning.
2. Trial fit the two wing halves together by blocking
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up both tips 3/16" (use the 3/16" x 3/16" x 4" blocks
provided) and the center at the trailing edge 7/16" (use the
"7/16" x 7/16" x 4" block provided).Use your T-bar to sand the
center rib to a slight angle, so the wing halves mate properly
at the center.
3. Place waxed paper under the center joint, then mix
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up a batch of epoxy (or aliphatic resin may be used), and apply
a thin layer to the center rib. Push the two wing panels
together with both lips blocked up 3/16" and the trailing edge
up 7/16". Pin the wing halves together, carefully double-
check alignment of the two halves, and allow the glue to fully
harden.
D 4. Sand the center joint smooth.
D 5. Sand the flat area on the LE at the center, as shown
on the plan. As you are sanding, trial fit the wing in the wing
saddle. There should be approximately 1/32" to 1/16" "slop"
in the fit of the wing to the saddle, to allow for fiberglass and
covering.

FIBERGLASS CENTER JOINT

IMPORTANT: This wing does not use plywood dihedral
braces. Therefore, it is absolutely necessary to reinforce the
center of the wing by applying 2" -wide fiberglass cloth, top and
bottom.
NOTE: If you have previous experience with applying fiberglass,
feel free to use your favorite method, providing that it results in a
strong bond between the glass cloth and the wood. If this is your
first time, we offer the following suggested method, which is the
fastest and easiest we have seen.
1. Make location marks for the fiberglass reinforce-
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ment cloth, 1-inch each way from the wing centerline.
2. Spray a very light mist of 3M "77" Spray Adhe-
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sive on the center section in the area to be glassed. Hold the
spray can at least 12" away from the surface when doing
this to avoid a heavy buildup. The purpose of this is only to
give the wood a little "tackiness". If you apply loo much
spray it could result in a poor glue bond.
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2"