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3. Once the detail parts have been built into the sub assemblies 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 allot 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 depen-
dency 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 mechanics, almost all of these concerns have been
considered and finished at the factory.
4a. When making cutouts or holes in the surface of the fiberglass the best procedure is to drill a pilot hole using the 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 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 which will 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.
7. Spray cans vs Airbrushed finishes. The preference is left the to the modeler, many good paint jobs have been accom-
plished using the spray cans however in the long run a good spray can finish requires more attention than using an
airbrush. The answer is simple, you want a professional looking fuselage, not want a flying brick. We need not even
think or mention any type of paintbrush larger than 1/4" wide.
8. As for selecting the type of paint visit your local hobby shop and ask their opinion on painting fiberglass. On a general
note, polyurethane is always a very safe paint that is fuel proof. A perfect paint job can be easily ruined by spilling raw
15-30% fuel accidentally. There is no paint manufacturer who will tell you that their product will resist 30% fuel for very
long and for the most part the fuselage is only exposed to the oil residue from the burned exhaust. The restricted fuelling
areas in a scale helicopter are prone to having fuel spills from time to time. For this reason, it is recommended to paint
the area around the engine and fuel tank, especially the edges of the fiberglass opening where paint runs are likely to
start. A good hobby shop will carry a bottle of clear polyurethane in liquid form just for this purpose. Thinned epoxy
works well as an alternate.
Good luck with your paint schemes and painting job undertakings.
