RC Pylon Racing-2012/04

www.ModelAviation.com April 2012 Model Aviation 127
Materials:
1. Drywall spackle
2. Transtar 6411 Finish-Tec 2K Kwik
Prime Primer Surfacer Yellow
3. 220-grit sandpaper
4. 20-gallon air compressor
5. Air compressor blow gun
6. Air regulator and water filter
attached to an air compressor hose
7. Blue Scott-brand shop towels
8. HVLP touch-up spray gun (5- to
8-ounce cup). I have two guns in the
arsenal. One is a 5.3-ounce touch-up
gun from Harbor Freight that costs
approximately $40. This works well for
trim colors that have more area, such
as the red on the airplane pictured with
this article. I have painted many models
(including base color and clearcoat)
with this spray gun and produced good
results.
The other is a DeVilbiss I purchased
a couple of years back that works
well for the clear and base colors.
The DeVilbiss StartingLine Mini
Detail and Touch-Up HVLP Spray
Gun costs nearly $80. I do not regret
investing a little extra for this gun. It
has an 8.5-ounce metal cup, which
makes cleanup easier, and is about
the right volume for clearcoating an
entire airframe using an air pressure of
approximately 30 psi.
9. Paasche or comparable air brush;
single action is fine.
10. 1/8-inch-wide Scotch 471-series
blue plastic fine-line striping tape or
K-TAPE 1/8-inch wide orange fine-line
masking tape
11. 1/2-inch and 2-inch-wide 3M
Automotive Refinish tape
P ainting a racer can seem like an intimidating task
because of the unknowns and all of the stories told
about painting gone wrong. In this two-part series
I will attempt to provide information to help ease the
learning curve of painting our racing models.
I enjoy painting because it allows me to customize the paint scheme, letters,
graphics, and colors to my liking. Many of the current composite Q-500 and Q-40
models come painted in the mold. The tips and techniques I will describe in this
article can be applied to customizing these racers as well.
Throughout the years, Lyle Larson has provided me with great information and
allowed me to avoid a number of painful mistakes. However, I have also discovered
my own list of interesting ways to mess up a paint job. For truth-in-advertising
purposes, here are my top two favorite “lessons learned the hard way.”
1. Make sure the little vent hole in the top of your high-volume, low-pressure
(HVLP) spray gun is not clogged. This leads to a confetti-like
spray of material from the spray gun, similar to Silly String.
2. Do not attempt to paint if the temperature is below
60° and your hardener is designed for 70°-plus weather. This
leads to depressing sags and runs that become evident before
the clearcoat sets.
I spent some time at Lyle Larson’s Speed Pros shop in early
January, painting a new Proud Bird II for the February Phoenix Q-40
Classic race. Speed Pros is roughly 20 minutes from my home and is
located in Piedmont, South Dakota.
Lyle has produced Q-40 models for racers around the world,
and pumped out 56 in 2011. Lyle has painted hundreds, if not
thousands, of models throughout the years and has the process down
to a fine art.
The art of painting—there is far more art involved than science—
can be read about, but you have to jump in and try it. You may
make a few mistakes, but given a little time and patience, you can
produce some beautiful paint jobs.
Painting Tips and
Techniques, Part One
by Aaron “AJ” Seaholm
[email protected]
PLUS:
> Miss Dara EF1
The author’s airplane wing has a dull finish
before applying the clearcoat.
The author’s Speed Pros Proud Bird II Q-40
racer is painted with techniques outlined in
this month’s article.
128 Model Aviation April 2012 www.ModelAviation.com
12. GerberMask Ultra stencil
material, cut with your numbers and
graphics. Jim Allen, from Fast Lane
Graphics near Phoenix, cuts stencils at a
reasonable price.
13. PPG Deltron (DBU) and
activator or PPG ShopLine basecoat
paints. During my visit to Lyle’s
shop, we painted two Proud Birds; he
used ShopLine and I used DBU. The
ShopLine went on thinner and only
needed lacquer thinner to reduce, while
the DBU requires an activating reducer.
The lacquer thinner reduction of
the ShopLine series allows the excess
to be poured back into the can, which
saves on waste. These paints are not
cheap; minimizing waste is definitely
a good thing. I plan to begin replacing
my exhausted DBU supply with PPG
ShopLine basecoat in the future.
14. Lacquer thinner for gun cleanup
and reducing ShopLine basecoats
15. Clearcoat, 630 ShopLine clear or
PPG DC3000
16. JC605 basecoat blender by PPG
ShopLine
17. Heat gun
After you have secured the
materials—and recovered from the
price tag—it is time to start. Keep in
mind that even with the minimum pint
for your base color, half pints for trim
colors, and a quart of clear, you have
purchased roughly enough paint for a
dozen models. The initial investment
for the materials will be in the $500-
plus price range.
To prepare the model for painting,
use drywall spackling and smear the
non-painted fiberglass areas. Thinning
the spackling with water makes this
process easier. Allow the coating to dry
and then use 220-
grit sandpaper to
sand away the excess
material.
If you look closely,
you will see many
pinholes full of white
spackling. Wipe the
fuselage down with
a paper towel and
spray a liberal coat
of primer with your
HVLP spray gun.
Sand the primer
down with 220-grit
sandpaper until the
fiberglass begins to
show through the
primer. Primer is
heavy and can add
substantial weight if
not removed from
the airframe.
With the surface
prepared, it is time
to spray the base
color over the entire
airframe. Blow off
the fuselage and wing
with the blow gun to
get the dust out of
those cracks and crevices.
Wipe all the surfaces down
with a Scott-brand shop towel and
blow off the fuselage again.
Be careful not to get the blow gun
too close to the skinned hinge lines
of the tail and wing. Excess pressure
that builds up in the interior of a
hollow composite structure can lead to
delaminating skins off the spars.
Spray the entire airframe with
basecoat and apply just enough paint
to get a uniform color. The first time
you spray basecoat, you will notice the
shine dulls rapidly as the paint dries.
This is normal and usually only takes a
few minutes. Try to focus on applying a
uniform color and do not focus on the
sheen. The clearcoat will provide the
shine for the basecoat/clearcoat paint
system.
Set your air regulator to approximately
30 psi for shooting the basecoat and
use your HVLP touch-up gun. If you
see a small pinhole that was missed
with the initial spackling and primer
step, use your finger to fill in the
blemish with spackling and shoot some
basecoat over the top of the area—
another Lyle trick.
After it’s dry (usually 15 to 30
minutes maximum; less if you dry
with a heat gun), mask out your paint
scheme with 1/8-inch fine-line tape.
Apply the GerberMask stencils for
numbers and other graphics.
I typically put the wing on the
fuselage to ensure the wing stripes
have the same offset left and right
from the fuselage. When the color
scheme fine-line masking is complete,
mask off the area not needing color
using 3/4-inch and 2-inch-wide 3M
Automotive Refinish tape and paint
your first trim color.
For smaller stripes, use your airbrush
to apply the color. Use a tack cloth
and blow off the surface with your air
compressor blow gun before shooting
the color. These basecoat colors will be
rc pyloff snca rlaeci ng
Gary Schmidt’s new Dan Kane Jr. and Jerry Small-designed
Miss Dara Electric Formula 1 is nearly ready for action.
Below: Side-by-side photo of the Q-40 fuselage in primer and
painted by Lyle Larson, using the PPG ShopLine series basecoat
and clearcoat paint system.
dry in minutes. If you cannot wait, use
a heat gun to accelerate the process. Be
careful because it is easy to loosen the
tape or cause other unwanted effects.
Repeat the masking process until your
color scheme is complete. Remember to
use your finger to firmly press the tape to
the surface. A credit card also works well
for pressing the tape to get that crisp line
you desire.
Carefully remove all fine-line and
masking tape. Thoroughly wet a Scott
shop towel with water only and wipe
down the entire airplane. Do not wipe
it down dry, or with wax and grease
remover. The darker basecoat can bleed
and impregnate the lighter colors. Wipe
dry and blow off with your blow gun.
Another good trick is to use 2-inch
masking tape to remove flakes generated
from pulling up the fine line tape. Gently
stick and remove at the edges of the
colors, particularly the letters. This will
grab any material and help lessen the
edge of the colors.
In part two of this series, I will walk
you through the process of applying
clearcoat. Clear can be tricky and I will
give this process the attention it deserves
in the next article. If you cannot wait
until June, don’t hesitate to send me an
email to get the basics for those winter
projects.
Miss Dara
Gary Schmidt sent in a write-up and
photo for his current National Miniature
Pylon Racing Association (NMPRA)
Electric Formula 1 (EF1) project:
Miss Dara.
“Just thought I would send you some
pictures on my new EF1, ‘Miss Dara.’ It
still needs the radio installed and flight
surfaces hooked up, but those should be
done soon. The model was constructed
from Dan Kane’s laser-cut kit and went
together very easily.
“The primary structure is wood with
a fiberglass cowl and wheel pants. There
is also a plastic canopy and turtle deck
made by Jerry Small. The only changes I
made were to completely sheet the wing
and substitute a solid vertical tail instead
of the lightened version supplied with the
kit. I like the solid wing look without rib
bays and the solid tail should be good for
those hard launches.
“The finish is MonoKote over the
wood structures, with PPG MonoKote
matching paint from Radio South over
the fiberglass and plastic pieces. The
black checkers and graphics are vinyl,
made by Jim Allen of Fast Lane Graphics.
It is powered with an Arrowind 2820
motor, Castle Creations Ice Lite 75 speed
control, and a Thunder Power 4s battery
pack.
“Radio-wise, as if you could not tell
by the photo, it is all Futaba, including a
R617FS receiver, S9650 elevator servo,
and S3156 servos for the aileron halves
and rudder. I am looking forward to
getting it done and flying. I hope to play
around with it during practice for the big
Q-40 race in Phoenix this February, as
well as hit a race or two during 2012.”
Great looking EF1; thanks for sending
it in, Gary.
Have fun, race hard!
Sources:
NMPRA
www.nmpra.org
Speed Pros
(605) 787-6340
www.calspeedpros.com
DeVilbiss
(800) 992-4657
www.devilbiss.com
Harbor Freight Tools
(800) 423-2567
www.harborfreight.com
3M/Scott
(877) 856-7268
http://solutions.3m.com/en_US/Products
Paasche Airbrush Company
(773) 867-9191
www.paascheairbrush.com
Gerber Scientific Products
(800) 222-7446
www.gspinc.com
PPG Industries
(800) 647-6050
https://buyat.ppg.com/refinishProductCatalog