CL Aerobatics - 2012/03

ff scale
www.ModelAviation.com March 2012 Model Aviation 139
cl aerobatics
Because I applied the white basecoat more than a year before I applied the trim,
I had to scuff the paint’s surface using a 3M Scotch-Brite Ultra Fine Hand Pad (part
number 37448) before applying the trim colors. If the ChromaBase paint is allowed
to dry or “cure” for more than 48 hours, subsequent coats of paint, trim, or clear will
not adhere properly. Scuffing the surface breaks the “skin” of the paint and yields
some “tooth” for subsequent layers of paint or clear.
I applied the original coats of white basecoat paint using an Iwata HVLP “baby
series” spray gun (part number LPH-50-062G). Auto body people usually refer to
this gun as a “jam gun” because it is typically used to spray small areas such as door
jams on cars.
I’ve owned a number of spray guns and the Iwata is the
best one I’ve owned and used for painting models. It put
down an extremely flat, smooth layer of white ChromaBase
paint, and when it dried I was happy with the surface.
When I used the Scotch-Brite pad to scuff the eggshelllike
surface a year later, the result was a matte, flat surface that had no obvious
flaws and looked absolutely even and smooth, even when examined closely. I was
delighted with this working surface on which to apply trim colors!
My good friend, Buddy Wieder, had finished his Ryan’s Eagle using the
ChromaBase system a year earlier and he also had let the basecoat of white sit for
more than 48 hours before beginning to apply the trim colors. He did not scuff the
surface with the Scotch-Brite pad before applying the trim and didn’t experience
any adhesion problems. Perhaps he just got lucky.
Buddy tried several types of tape for laying out the trim on his model, and found
that the 3M Scotch 471 Series Blue Fine Line Tape worked best for him on the
ChromaBase paint’s surface. He didn’t need to seal the edges with clear before
spraying on the trim colors.
This paint covers incredibly well. Because it can be sprayed on in thin layers and
dries quickly, sealing the edges of the tape is unnecessary. Buddy also found out that
there is no need to clean up the paint
edges by scraping them with a credit card
or other tool. When the tape is peeled
back, the edge is perfect and when the
thin layer of paint is applied properly, it’s
almost imperceptible to the touch.
While I applied the trim to the
Crossfire Extreme, I experimented with
Scotch Fine Line Blue Tape and Scotch
218 Series Green Polypropylene Fine
Line Tape. The Fine Line Blue Tape
is superior when working with the
ChromaBase paint system. It has the
proper amount of tack, and is easy to
position and easy to work around curves,
although there are not many curves in
the Crossfire Extreme’s paint scheme.
There was no tendency for the tape
to pull up the basecoat of paint as I
removed it from the airplane after
painting. This can be a problem with
dope-based finishes, especially when a
blocking coat of silver has been used.
The silver dope (and dope products in
general) does not grip the model nearly
as well as do the ChromaBase paints.
To be fair, I have not yet tried to use
a ChromaBase silver as a blocking coat
under the white basecoat. I plan to try
In my January 2012 column, I related
the story about the finishing of my
Crossfire Extreme, shortly before
last year’s Nats. To recap a bit, I used
the DuPont ChromaBase Basecoat/
Clearcoat paint system to finish the
model in record time (at least for me).
A freak accident, resulting in
severe damage to the wing a week
before leaving for the Nats, led to my
discovery that ChromaBase paints
are also easy to repair. I promised to
write more about painting with the
ChromaBase paint system.
Trimming with
ChromaBase
paints
by Bob Hunt
[email protected]
PLUS:
> Computer graphics
Phil Granderson scored 20 appearance points at the 2008 Nats and won the Pilots’ Choice
Concourse award with his original-design Zealot. Phil designed and cut his own stencils for
the elaborate trim scheme. Gene Martine photo.that soon and I have even purchased the
paint.
Why the silver? Metallic paints of any
type show off and even amplify flaws in
the surface preparation, and can be used
as an “indicator coat.” After this coat of
silver has been applied you can critically
examine the model’s base finish and
fix the flaws before applying the actual
color coats.
Silver is close to the color value
of white, and many—if not most—
competition CL Stunt models feature
white as the base color. It takes less white
paint to cover silver than it does to cover
a darker, blotchier basecoat.
Having written that, I’ll tell you that I
sprayed the white coat on the Crossfire
Extreme over the filled and sanded
0.2-ounce carbon fiber that I used to
cover the entire model. The carbon is
black and is probably the toughest to
cover with white paint. To my surprise,
one coat of ChromaBase white covered it
completely!
Could I have saved weight by using
the silver paint first, as an indicator/
primer coat? I intend to try it on my next
airplane and keep accurate weight records
as I go. Working the surface of the silver
paint with the Ultra Fine Scotch-Brite
Pad will yield a perfect base on which
to apply the basecoat of color paint, so I
need to try it.
cl aerobatics
Metallic paint tends to cover more
quickly and add less weight per coat.
A thin coat of silver that is burnished
even thinner using the Scotch-Brite pad
might be the very best blocking and
primer-coat option.
Trimming with ChromaBase Paints
The most fun part of the finishing
process for me is applying the color trim
to the airplane’s surface. This is usually
a multiday process, applying no more
than one trim color per day. With the
ChromaBase paints, that has changed!
The ChromaBase paints dry so quickly
that you can easily apply three, four, or
even five trim colors in one day.
I usually have to wait several hours
to ensure that the paint has dried
before removing the masking tape
when I use dope colors for trim. With
the ChromaBase paints, I could shoot
the paint, set the gun down, and begin
unmasking with no fear that there
would be any ragged edges or any
tendency for the substrate (basecoat) to
pull up with the tape.
One reason for this is the ChromaBase
paint’s amazing coverage properties.
Only a single, thin coat of color is
required, and because of that the paint
dries almost instantly. It does not have
enough buildup to cause a significant
edge that needs to be cleaned up
afterwards.
Typically, I let the trim paint set for
about a half hour before masking over it
to prepare for the next trim color. You
can apply multiple trim colors in a short
amount of time, and you can apply each
subsequent color’s masking trim overthe previous color trim areas without
fearing that you will pull up the trim
that you just applied.
Add to this the fact that you can spray
during virtually any type of weather, and
you can see where this is an efficient
painting method for those who are late
in getting their models painted for the
season. No humidity worries at all!
Little trim color is required for an
average airplane, so you can buy your
paint in half-pint quantities and then
mix it one-to-one with the reducer (not
hardener—this paint is air dry and does
not require a catalyst) before spraying. A
half pint turns into a full pint of material
when reduced, and that should last a
long time. The paint is expensive, but it
goes a long way!
You knew that there would be a
negative somewhere in this system. I
found that some of the colors I used
for trim would dissolve a bit when
wiped with DuPont Prep-Sol cleaner or
Final-Klean, and the color would smear
out onto the white base. Yuk! I had to
respray white in a few places when this
happened, and I was fearful that I would
not be able to adequately clean the
airframe before applying the two-part
clear coat without further smearing the
colors.
I spoke with the technician at my local
auto paint store and he told me that I
should seal the colors with a thin coat of
DuPont’s 380 clear; this would prevent
the cleaner from dissolving the color. I
spoke with a friend of mine who is an
auto body man, and he told me that he’s
never had the smearing problem that I
encountered. I talked with my lifelong
friend, Phil Granderson, about this
smearing problem and he told me that
if you use Windex to clean the model
before applying the clear coats, you will
not have any problems.
I carefully cleaned up to and around
the color-trimmed areas on the Crossfire
Extreme, but did not actually seal the
colors with any non-catalyzed clear before
applying the two-part clear coat and I had
no problems with contamination. I intend
to seal the color-trim areas on my next
painted model and I’ll report the results.
I have had such good results with the
system I have used to-date that I have no
hesitancy in recommending it to others.
Lettering and Numbers
In the past, I used to create my own
painting stencils for letters and AMA
numbers. I used the low-tack, Con-Tact
brand shelf paper available at most
grocery stores and home-improvement
centers. It worked fine, but it was a lot of
work to transfer the designs that I wanted
from tracing paper to the contact paper
and then cut out the designs cleanly. Old
technology!
The computer age has afforded us
many things for our modeling, but when
it comes to the painting process we’ve hit
the digital jackpot! For the past several
years, computer-cut stencils have been
the way to go to apply clean, crisp, fast
detailing on our models.
On the Crossfire Extreme I used
computer-cut painting stencils for the
first time; yes, I’m old-fashioned and notprone to be the first one to try some of
these new-fangled things. I love them!
Phil Granderson has been in the
graphics industry for most of his life
and he has been making computer-cut
graphics and stencils for his personal
airplanes for several years. He’s a master
designer, craftsman, and painter. His
paint schemes are augmented with an
abundance of creative lettering elements
and computer-generated graphics.
Phil’s Zealot design sat all alone on
the front row at the 2008 Nats, and
it displayed all of Phil’s considerable
talents for graphic design and finishing.
It was one of the very few 20-point
appearance models in the history of the
Nats and it also captured the coveted
Pilots’ Choice Concourse award.
Shortly after that model appeared
at the Nats, many other fliers began to seriously experiment with more creative letters and numbers on their models and
using computer-designed and computercut
graphics.
Jim Aron’s Systrema is one such
model. It sat on the Nats front row with
20 appearance points and received the
Concourse award. Jim created the trim
scheme design and worked with Phil to
produce the many stencils required to
finish the job.
It will take me a while to warm up tosome of the wild graphics and schemes
that are now being applied to some
of the models seen at the Nats, but I
certainly applaud the creativity and the
forward-thinking application of a new
technology to our discipline.
I finally conceded to technology and
asked Phil to cut me a couple of stencils
for my Crossfire Extreme. I chose a font
and a size and sent a file to Phil.
What I received in return were several
ready-to-use sets of stencils. I measured
and made alignment marks on small
pieces of tape that I applied to the wing’s
surface, peeled the backing sheet off of
one of the stencils, and with my buddy
Joe Adamusko’s help, deftly applied the
stencil perfectly flat against the wing. The
outer sheet was peeled back to reveal a
perfectly aligned and sealed stencil.
“This is just cheating,” I thought. That
thought became even more entrenched
when I sprayed the ChromaBase Fleet
Black onto the stencil, let it dry, and
then began to unmask the wing. I’ve
never had a more perfect result in
painting letters and numbers! I highly
recommend that if you have not yet
tried computer-cut stencils, you should
try them on your next model!
If you are interested in trying either
computer-cut painting stencils, or
computer-generated and cut appliqués,
I recommend contacting Tom Niebuhr
who owns Blue Sky Models. Tom cuts
custom masks for lettering, graphics, and
vinyl appliqués, and can also provide
made-to-order decals. He provided me
with examples of his work and it is
outstanding.
Tom can work from any True Type fontand has hundreds of them available. His
contact information is listed in “Sources.”
One Last Thought
My final thought on using any of the
basecoat/clearcoat systems is that there
is an abundance of information available
in data sheets from the manufacturers
of these paint systems. I suggest
downloading them from the various
websites and studying them before
trying this type of paint.
There are dozens of video how-tos
available for viewing on YouTube, so
search a bit and you will learn a lot.
Till next time, fly Stunt!

ff scale
www.ModelAviation.com March 2012 Model Aviation 139
cl aerobatics
Because I applied the white basecoat more than a year before I applied the trim,
I had to scuff the paint’s surface using a 3M Scotch-Brite Ultra Fine Hand Pad (part
number 37448) before applying the trim colors. If the ChromaBase paint is allowed
to dry or “cure” for more than 48 hours, subsequent coats of paint, trim, or clear will
not adhere properly. Scuffing the surface breaks the “skin” of the paint and yields
some “tooth” for subsequent layers of paint or clear.
I applied the original coats of white basecoat paint using an Iwata HVLP “baby
series” spray gun (part number LPH-50-062G). Auto body people usually refer to
this gun as a “jam gun” because it is typically used to spray small areas such as door
jams on cars.
I’ve owned a number of spray guns and the Iwata is the
best one I’ve owned and used for painting models. It put
down an extremely flat, smooth layer of white ChromaBase
paint, and when it dried I was happy with the surface.
When I used the Scotch-Brite pad to scuff the eggshelllike
surface a year later, the result was a matte, flat surface that had no obvious
flaws and looked absolutely even and smooth, even when examined closely. I was
delighted with this working surface on which to apply trim colors!
My good friend, Buddy Wieder, had finished his Ryan’s Eagle using the
ChromaBase system a year earlier and he also had let the basecoat of white sit for
more than 48 hours before beginning to apply the trim colors. He did not scuff the
surface with the Scotch-Brite pad before applying the trim and didn’t experience
any adhesion problems. Perhaps he just got lucky.
Buddy tried several types of tape for laying out the trim on his model, and found
that the 3M Scotch 471 Series Blue Fine Line Tape worked best for him on the
ChromaBase paint’s surface. He didn’t need to seal the edges with clear before
spraying on the trim colors.
This paint covers incredibly well. Because it can be sprayed on in thin layers and
dries quickly, sealing the edges of the tape is unnecessary. Buddy also found out that
there is no need to clean up the paint
edges by scraping them with a credit card
or other tool. When the tape is peeled
back, the edge is perfect and when the
thin layer of paint is applied properly, it’s
almost imperceptible to the touch.
While I applied the trim to the
Crossfire Extreme, I experimented with
Scotch Fine Line Blue Tape and Scotch
218 Series Green Polypropylene Fine
Line Tape. The Fine Line Blue Tape
is superior when working with the
ChromaBase paint system. It has the
proper amount of tack, and is easy to
position and easy to work around curves,
although there are not many curves in
the Crossfire Extreme’s paint scheme.
There was no tendency for the tape
to pull up the basecoat of paint as I
removed it from the airplane after
painting. This can be a problem with
dope-based finishes, especially when a
blocking coat of silver has been used.
The silver dope (and dope products in
general) does not grip the model nearly
as well as do the ChromaBase paints.
To be fair, I have not yet tried to use
a ChromaBase silver as a blocking coat
under the white basecoat. I plan to try
In my January 2012 column, I related
the story about the finishing of my
Crossfire Extreme, shortly before
last year’s Nats. To recap a bit, I used
the DuPont ChromaBase Basecoat/
Clearcoat paint system to finish the
model in record time (at least for me).
A freak accident, resulting in
severe damage to the wing a week
before leaving for the Nats, led to my
discovery that ChromaBase paints
are also easy to repair. I promised to
write more about painting with the
ChromaBase paint system.
Trimming with
ChromaBase
paints
by Bob Hunt
[email protected]
PLUS:
> Computer graphics
Phil Granderson scored 20 appearance points at the 2008 Nats and won the Pilots’ Choice
Concourse award with his original-design Zealot. Phil designed and cut his own stencils for
the elaborate trim scheme. Gene Martine photo.that soon and I have even purchased the
paint.
Why the silver? Metallic paints of any
type show off and even amplify flaws in
the surface preparation, and can be used
as an “indicator coat.” After this coat of
silver has been applied you can critically
examine the model’s base finish and
fix the flaws before applying the actual
color coats.
Silver is close to the color value
of white, and many—if not most—
competition CL Stunt models feature
white as the base color. It takes less white
paint to cover silver than it does to cover
a darker, blotchier basecoat.
Having written that, I’ll tell you that I
sprayed the white coat on the Crossfire
Extreme over the filled and sanded
0.2-ounce carbon fiber that I used to
cover the entire model. The carbon is
black and is probably the toughest to
cover with white paint. To my surprise,
one coat of ChromaBase white covered it
completely!
Could I have saved weight by using
the silver paint first, as an indicator/
primer coat? I intend to try it on my next
airplane and keep accurate weight records
as I go. Working the surface of the silver
paint with the Ultra Fine Scotch-Brite
Pad will yield a perfect base on which
to apply the basecoat of color paint, so I
need to try it.
cl aerobatics
Metallic paint tends to cover more
quickly and add less weight per coat.
A thin coat of silver that is burnished
even thinner using the Scotch-Brite pad
might be the very best blocking and
primer-coat option.
Trimming with ChromaBase Paints
The most fun part of the finishing
process for me is applying the color trim
to the airplane’s surface. This is usually
a multiday process, applying no more
than one trim color per day. With the
ChromaBase paints, that has changed!
The ChromaBase paints dry so quickly
that you can easily apply three, four, or
even five trim colors in one day.
I usually have to wait several hours
to ensure that the paint has dried
before removing the masking tape
when I use dope colors for trim. With
the ChromaBase paints, I could shoot
the paint, set the gun down, and begin
unmasking with no fear that there
would be any ragged edges or any
tendency for the substrate (basecoat) to
pull up with the tape.
One reason for this is the ChromaBase
paint’s amazing coverage properties.
Only a single, thin coat of color is
required, and because of that the paint
dries almost instantly. It does not have
enough buildup to cause a significant
edge that needs to be cleaned up
afterwards.
Typically, I let the trim paint set for
about a half hour before masking over it
to prepare for the next trim color. You
can apply multiple trim colors in a short
amount of time, and you can apply each
subsequent color’s masking trim overthe previous color trim areas without
fearing that you will pull up the trim
that you just applied.
Add to this the fact that you can spray
during virtually any type of weather, and
you can see where this is an efficient
painting method for those who are late
in getting their models painted for the
season. No humidity worries at all!
Little trim color is required for an
average airplane, so you can buy your
paint in half-pint quantities and then
mix it one-to-one with the reducer (not
hardener—this paint is air dry and does
not require a catalyst) before spraying. A
half pint turns into a full pint of material
when reduced, and that should last a
long time. The paint is expensive, but it
goes a long way!
You knew that there would be a
negative somewhere in this system. I
found that some of the colors I used
for trim would dissolve a bit when
wiped with DuPont Prep-Sol cleaner or
Final-Klean, and the color would smear
out onto the white base. Yuk! I had to
respray white in a few places when this
happened, and I was fearful that I would
not be able to adequately clean the
airframe before applying the two-part
clear coat without further smearing the
colors.
I spoke with the technician at my local
auto paint store and he told me that I
should seal the colors with a thin coat of
DuPont’s 380 clear; this would prevent
the cleaner from dissolving the color. I
spoke with a friend of mine who is an
auto body man, and he told me that he’s
never had the smearing problem that I
encountered. I talked with my lifelong
friend, Phil Granderson, about this
smearing problem and he told me that
if you use Windex to clean the model
before applying the clear coats, you will
not have any problems.
I carefully cleaned up to and around
the color-trimmed areas on the Crossfire
Extreme, but did not actually seal the
colors with any non-catalyzed clear before
applying the two-part clear coat and I had
no problems with contamination. I intend
to seal the color-trim areas on my next
painted model and I’ll report the results.
I have had such good results with the
system I have used to-date that I have no
hesitancy in recommending it to others.
Lettering and Numbers
In the past, I used to create my own
painting stencils for letters and AMA
numbers. I used the low-tack, Con-Tact
brand shelf paper available at most
grocery stores and home-improvement
centers. It worked fine, but it was a lot of
work to transfer the designs that I wanted
from tracing paper to the contact paper
and then cut out the designs cleanly. Old
technology!
The computer age has afforded us
many things for our modeling, but when
it comes to the painting process we’ve hit
the digital jackpot! For the past several
years, computer-cut stencils have been
the way to go to apply clean, crisp, fast
detailing on our models.
On the Crossfire Extreme I used
computer-cut painting stencils for the
first time; yes, I’m old-fashioned and notprone to be the first one to try some of
these new-fangled things. I love them!
Phil Granderson has been in the
graphics industry for most of his life
and he has been making computer-cut
graphics and stencils for his personal
airplanes for several years. He’s a master
designer, craftsman, and painter. His
paint schemes are augmented with an
abundance of creative lettering elements
and computer-generated graphics.
Phil’s Zealot design sat all alone on
the front row at the 2008 Nats, and
it displayed all of Phil’s considerable
talents for graphic design and finishing.
It was one of the very few 20-point
appearance models in the history of the
Nats and it also captured the coveted
Pilots’ Choice Concourse award.
Shortly after that model appeared
at the Nats, many other fliers began to seriously experiment with more creative letters and numbers on their models and
using computer-designed and computercut
graphics.
Jim Aron’s Systrema is one such
model. It sat on the Nats front row with
20 appearance points and received the
Concourse award. Jim created the trim
scheme design and worked with Phil to
produce the many stencils required to
finish the job.
It will take me a while to warm up tosome of the wild graphics and schemes
that are now being applied to some
of the models seen at the Nats, but I
certainly applaud the creativity and the
forward-thinking application of a new
technology to our discipline.
I finally conceded to technology and
asked Phil to cut me a couple of stencils
for my Crossfire Extreme. I chose a font
and a size and sent a file to Phil.
What I received in return were several
ready-to-use sets of stencils. I measured
and made alignment marks on small
pieces of tape that I applied to the wing’s
surface, peeled the backing sheet off of
one of the stencils, and with my buddy
Joe Adamusko’s help, deftly applied the
stencil perfectly flat against the wing. The
outer sheet was peeled back to reveal a
perfectly aligned and sealed stencil.
“This is just cheating,” I thought. That
thought became even more entrenched
when I sprayed the ChromaBase Fleet
Black onto the stencil, let it dry, and
then began to unmask the wing. I’ve
never had a more perfect result in
painting letters and numbers! I highly
recommend that if you have not yet
tried computer-cut stencils, you should
try them on your next model!
If you are interested in trying either
computer-cut painting stencils, or
computer-generated and cut appliqués,
I recommend contacting Tom Niebuhr
who owns Blue Sky Models. Tom cuts
custom masks for lettering, graphics, and
vinyl appliqués, and can also provide
made-to-order decals. He provided me
with examples of his work and it is
outstanding.
Tom can work from any True Type fontand has hundreds of them available. His
contact information is listed in “Sources.”
One Last Thought
My final thought on using any of the
basecoat/clearcoat systems is that there
is an abundance of information available
in data sheets from the manufacturers
of these paint systems. I suggest
downloading them from the various
websites and studying them before
trying this type of paint.
There are dozens of video how-tos
available for viewing on YouTube, so
search a bit and you will learn a lot.
Till next time, fly Stunt!