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COVERING AND FINISHING
No matter what brand and type of covering material you decide to use (iron-on plastic, iron-on fabric, or bare cloth and
paint) the surface of your uncovered model directly affects what the covering job will look like when you are done. Poor
workmanship will show right through. Now is the time to carefully inspect the surface of the entire model. Carefully sand
smooth any mis-matched sheeting joints. Use a good quality, light weight filler to fill in any dents, nicks, or dings. The
entire model should be final sanded with 220 grit sandpaper, progressing to 360 grit. The surfaces to be covered must be
clean, dry and dust-free. Use a tack rag and/or compressed air to make sure the model is completely dusted. We would
also suggest that you make sure the physical area where you will be covering the model is as clean and dustfree as
possible.
Fuel Proofing
Before covering the fuselage, coat the entire front surface of the firewall with two or three coats of SIG Clear Dope,
polyester or epoxy resin, and other fuel proof paint. Also, fuel proof the grooves on the main gear blocks and around the
door opening.
Covering The Wings
146a.
Begin by covering the ends of the aileron bays. Run the covering material
around onto the top and bottom. Also, cover the W-1 end rib of the wing panel,
again run the covering around the top and bottom of the wing about 1/8".
BUILDERS TIP: An good way of open
small round holes in the covering, like
where the wing struts bolt on, is to
briefly heat the tip of a small diameter
Phillips screwdriver or an awl with a
butane torch. Then, quickly press the
tip into the covering film, directly over
the hole. The covering will melt
around the edge of the hole, sealing it
and leaving a perfectly round opening.
b.
Cover the bottom of the wing with one piece of covering material. Like all open
structures, you should seal the covering down all along the outside edges of the
structure first. At the root end of the wing panel, seal the covering over the edges
and onto the end rib. Along the back of the wing panel, slit the excess covering
at each end of the aileron bay and run the flap of covering material around the
corner and seal it on to the face of the aileron opening. In the aileron servo bay,
cut an "X" pattern, then iron the excess material inside the hatch area, against
the ribs and hatch rails.
c.
When all the edges are fastened down, cover the top side of the wing in similar
fashion.
d.
Shrink the top and bottom covering tight with a heat gun. Refer to instructions
that came with your covering material.
Covering The Ailerons
Start by covering both ends of the aileron with small scrap pieces. Then, cover the bottom with one piece, cutting a slot for
the horn. Finally, cover the top in one piece. Shrink both sides simultaneously with a heat gun.
Covering The Aileron Hatches
Start by applying an oversize piece of covering to the top of the hatch. Then turn
it over and cut out the excess at the corners to make it easier to wrap and seal
the covering around the edges. Continue wrapping and sealing the covering
around the edges and onto the bottom. Then, shrink the top surface tight.
Covering The Fuselage And Fin
On the full-size Cubs, the fuselage and fin are covered with one continuous piece of fabric. It bridges from the top
stringers of the fuselage sides up to fin rib, producing a beautiful fillet. The construction of this model duplicates this
feature. Your covering material should bridge from the balsa tail fairings up to the fin bottom rib and then, forward over the
top of the fuselage. This may at first sound like a difficult job, but it’s much easier than you’d think, if you proceed in the
right sequence.