Preparing and Painting
the Kit Version
This section is written to cover painting and
detailing of fiberglass components using in
Century’s scale helicopter kits. Some
included references may describe components
of different kits, not exclusive to this detail
instruction manual. Introduction
to Fibergass
When considering the strength compared to
the space age canopies that are common on
most pod and boom helicopters there is no
contest. This plastic material is virtually
indestructible at the penalty of being virtually
un-paintable without specialized and expensive
automotive primers and paints, there is also
a very limited range of color available. The
reason you are reading this page is that you
have come to your senses and wanted to fly
a model that looks and holds all the prestige
of a real helicopter.
Flexibility
A wonderful attribute of fiberglass is in
its flexibility. Century and Funkey take care
and pride in craftsmanship that goes into
every fuselage. However, fiberglass parts
will migrate (change shape) while inside the
shipping box. When two mating components are
brought together and they do not align or
mate, the culprit is a warped part. Many become
upset and wish to lay blame but dealing with
this is very simple when explained a simple
procedure. Using a heat gun set at the high
setting at a distance of 1-2 feet away, evenly
heat the warped part until the outside surface
is hot to the touch and the part has become
pliable (flexible). Using adhesive tape, mate
the two fiberglass parts together and let
both parts sit until both parts have reached
room temperature. Remove the tape and now
both parts are stable and match one another.
In some instances, depending on the location
of the warp, the part may need to be held
in an overextended position to achieve the
proper shape when the part is finished.
Working
with Fiberglass
Difficult to work with, we disagree. Fiberglass
is easier to repair than you think. Using
today’s CA type of adhesives, a severe
crack in a fuselage can be simply fixed and
the repaired section is much stronger than
in its original state. Add touchup paint and
no one would ever know it had been damaged.
There is a limit to this type of thinking
where purchasing the replacement fiberglass
part is simply cheaper and less work than
performing major reconstructive surgery.
The
Paint Job
There is no magic to a good paint job, the
true secret is time, patience and common sense.
A beginner who thinks that they can throw
paint onto a fuselage Friday night before
flying on Sunday is dreaming, the helicopter
would be flyable but even that is a stretch.
The average beginner will spend the better
part of a month to apply a good clean paint
job.
Preparing
the Fuselage for Painting
After opening the kit version of the fuselage,
examine all the fiberglass components to see
where work needs to be done to allow a simple
"bring up" of the fuselage. "Bring
up" describes the necessary steps to
complete all the jobs in order to start priming
the fiberglass parts. Typical work that is
done at this stage is rough sanding on seams
and jointed components, filling of surface
imperfections, adding panel lines and rivets,
cutting required holes and preparation for
priming.
1. Start
by thoroughly washing all fiberglass parts
in mild detergent and warm water, this will
remove anyresidue remaining from the molding
process. Next wipe down all the parts with
Acetone (from the hardware store). The Acetone
will remove all traces of oil or grease that
will affect the adhesion of two fiberglass
parts or between the paint and the fiberglass.
Now using fine steel wool or an abrasive pad
commonly used for scrubbing dishes, scuff
all surfaces that will be joined or receiving
paint. What is important to note here is that
we are breaking through the topmost resin
surface and creating the best surface for
adhesive or primer to adhere to.
The prepared finish will have very fine score
marks usually seen when the part is held to
the light at a slight angle.
2. This is the time to rough
sand any accessories or small parts, using
the 320 grit sandpaper, that will be assembled
and attached at different positions on the
fuselage. These can be marking lights, engine
exhausts, scale fuel tanks, horizontal and
vertical stabilizers, guns, antenna or any
scale details being bonded to the fuselage.
These accessories should be test assembled
to make sure that all parts are prepared,
and you will be able to see any problems that
may arise in trying to paint these parts.
Some thought should be put into how to hold
the part as it is being painted. Go ahead
and bond these parts at this time using the
slow CA glue. A quick note on adhesives, as
the fuselage resin is polyester, do not use
any regular 5-30 minute epoxies to bond two
fiberglass components together. Stability
is specially formulated for this purpose and
excellent for fillets. Epoxy and polyester
will not bond properly to one another, but
epoxy is good to bond unlike substances like
wood or metal to themselves or other parts.
3. Once the detail parts
have been built into sub assemblies, they
are ready to paint, use a filler in sections
that have gaps or slight surface imperfections,
occasionally there are voids (air bubbles
in the resin) that occur near the surface
that need to be filled. There are alot of
good fiberglass fillers on the market, it
is best to check with your local hobby shop
to get a recommended product. Try to stay
away from porous fillers designed for wood
as they will shrink and are not a good choice
for large areas.
4. Most major windows and
accessory holes have been precut by Century,
leaving only those that have a user dependency
like the type of exhaust system used on the
helicopter or the exact exit position for
the cooling fan shroud. For these fuselages
that have been explicitly designed for the
Century’s scale mechanics, almost all
of these concerns have been considered and
finished at the factory. This leaves the hole
for the exhaust, if you are using the recommended
scale muffler (CN3058 .32-.38 or CN3059 .46-.50)
then these dimensions have been included on
a template in the Scale Mechanics Manual for
the 30 size engine, the 46-50 requires a slight
adjustment.
4a. When making cutouts or
holes in the surface of the fiberglass the
best procedure is to drill a pilot hole using
a 1/16" drill bit at corners or along
a curve. Start with a permanent marker to
draw the opening or window. The pilot holes
serve to avoid leaving sharp corners which
given the nature of a model helicopter will
be the focal point for stress cracking originating
from corners. Once the holes have been made,
use the moto-tool for all other roughing cuts.
The cut off wheel is the best for straight
lines and either the sanding drum or the curved
stone is used for smoothing edges. If the
cut out is a window, do not use the moto-tool
for the final work. Switch to a sanding blocks,
square blocks of various sizes for straight
edges and round dowels for rounded corners.
4b. In the case of the exhaust
opening, it should end up being 1/8"
larger across the outside diameter of the
exhaust pipe that extends below the bottom
of the fuselage. After drawing the circle,
use grinding stone and move in small circles
until the hole is at the size wanted.
5. Priming the fuselage accomplishes
two tasks: firstly, the primer paint is designed
to aggressively adhere to the surface being
painted and provide the best surface for the
colored paint to adhere to; secondly, all
surface imperfections will become visible.
Depending on the particular imperfection,
light sanding with number 600 or 800 sand
paper and the second priming will take care
of 90% of the highly visible problems. The
remaining 10% need to be filled, let dry,
sanded again and then sprayed with the second
coat of primer. The primer process will be
repeated until the surface is as perfect as
your patience and time permit.
6. Select your paint color
and follow the directions on the particular
brand of paint being used as each manufacturer
has different requirements.
|