Begin Construction; Fuelproof The Fuselage; Join The Wing Halves; Mount The Engine - GREAT PLANES Piper J-3 Cub Instruction Manual

BEGIN CONSTRUCTION

Fuelproof the Fuselage

❏ 1. Coat the firewall and all other bare wood around the
firewall with fuelproof paint or 30-minute epoxy thinned with
alcohol. Fuelproof other areas of bare wood in the fuselage
that may be exposed to fuel or engine exhaust, such as the
fuel tank area and the front and back of the wing saddle.
❏ 2. Set the fuselage aside while the paint or epoxy dries.

Join the Wing Halves

❏ 1. Cut the covering 1/8" inside the edges of the opening
in the bottom of the Right Wing Panel for the aileron servo.
Use your Top Flite MonoKote
covering to the sides of the opening.
Note: You'll notice a piece of string that passes through the
covering at the location of the aileron servo. Don't remove
the string because you will use it to pull your aileron servo
cord through the wing later.
❏ 2. Use 30-minute epoxy to glue the two 1/8" x 1-1/8" x
5-1/4" [3mm x 28mm x 133mm] plywood Wing Joiners and
the 3/32" x 1-1/8" x 5-1/4" [2.4mm x 28mm x 133mm]
plywood wing joiner together. Wipe away any excess epoxy.
® ™
Trim Seal Tool to seal the
❏ 3. Test fit the wing halves with the wing joiner. If necessary,
sand any high spots on the root end of the wing panels so
there is no gap when you join them. Since the wing is built
with no dihedral, it can be built flat on your work surface.
Make a dry run of the following step without using any glue
so you will know how to clamp your wing together.
❏ 4. Tape a piece of wax paper or plan protector over your
work surface. Thoroughly coat the joiner pockets and the
mating ends of both wing halves with 30-minute epoxy. Set
the wing halves aside and proceed quickly. Coat all surfaces
of one half of the wing joiner with 30-minute epoxy and
place it in one of the wing halves. Coat the other half of the
joiner with 30-minute epoxy and join the other wing. Use a
piece of balsa or cardboard to wipe away excess epoxy. Use
masking tape to tightly tape the wing together. Use a tissue
dampened with alcohol to wipe away any more epoxy that
oozes out of the wing, then set the wing aside. Do not
disturb the wing until the epoxy has fully cured.

Mount the Engine

❏ 1. Cut or break the "spreader bar" from each Engine
Mount half. Carefully trim any extra material left by the
spreader bar from each mount half. The surfaces where the
spreader bars were attached must be smooth to allow the
mount halves to fit together. Trim the flashing off any rough
edges if necessary.
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