Great Planes Spirit 100 Sailplane Kit - GPMA0550 - Manual (Page 43)

D 8 Sand the edges of the fuse to nice rounded comers, as
shown in the cross sections on the plans
NOTE: When covering the fin, begin by applying a
1/2" wide strip of covering on each triangle at the base of
the fin Next, cover the rest of the f i n with pre-cut pieces
having a straight edge to overlap (1/8"+ overlap) the
strips you previously applied This is a tip you should
remember as it makes it a lot easier to cover "compound"
curves
FINAL SANDING
Check over the entire structure carefully, inspecting for any
poorly glued joints, gaps and "dings" Apply additional glue and/
or balsa filler as necessary then sand the entire structure smooth
using progressively finer grades of sandpaper
IMPORTANT: When applying the covering to the stab
and fin areas do not cut the covering while it is on the
structure Doing this leaves "cut lines" in the wood and
greatly weakens the structure Cut your piece of covering
to fit before applying it
COVERING
There are many different types of covering materials avail-
able these days but the iron on type coverings are by far the
easiest to use and in most cases the best suited for the job There
are also several different brands of iron-on coverings available
We recommend you use Top Flite Super Monokote for covering
your SPIRIT 100 due to this covering's higher strength Sailplanes,
which usually have higher "aspect ratio" wings (long and thin),
gain a great deal of strength from the covering This is evident by
gently twisting the wing before and after it is covered, it is hard
to believe the difference Because of this, the higher strength
coverings are best suited for sailplanes
The following are some covering tips we have learned over
the years but you should follow the instructions included with
your covering material.
Sand the surfaces as smooth as possible before starting to
cover the plane The finished covering job will only be as smooth
as the surface you started with
Recommended Covering Sequence:
1 Strips as described in above note
2 Rudder left side
3 Rudder right side
4 Bottom of elevator
5 Top of elevator
6 Fin left side
7 Fin right side
8 Slab bottom right side
9 Stab bottom left side
10 Slab top right side
11 Stab top left side
12 Fuse bottom
13 Fuse sides
14 Fuse lop
15 Bottom of left wing panels (inner and outer)
16 Bottom of right wing panels (inner and outer)
17 Top of left wing panels (overlap covering 1/4" at LE
and TE)
18 Top of right wing panels (overlap covering 1/4" at LE
and TE)
19 Ailerons and flaps or spoilers if installed
Use a fresh single-edge razor blade or hobby knife blade and
replace the blade as soon as it starts showing signs of dulling
Set the iron to the proper temperature by first applying a "test
strip" of covering on a scrap of balsa
Work outward, start by tacking the covering in place at the
comers and then start in the middle and work your way out to the
corners, gently pulling any wrinkles out as you go
Securely seal all edges Make sure the edges are firmly
sealed down to prevent the covering from pulling away at the
seams when shrinking the panel
CHECKING FOR WARPS
This is a very important step and should be done every
once in a while throughout the flying season A sailplane's wing
is most efficient when it is not twisted or warped at all "Wash-
out" (wing trailing edge twisted up at the tip) helps make a poor
wing design fly better by adding stability (preventing stalls) at
slow speeds but it cuts down on the wing efficiency at normal
speeds The SPIRIT 100's wing is designed to fly well at slow
speeds without any washout and therefore we recommend you
check to make sure the wings are "flat" using the following
procedure
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