Off With the Old, on With the New - 2009/02

IMAGINE THAT you’re at the flying field
at 10 a.m. on a bluebird-fine Saturday
morning. There are clear skies with no wind,
and the happy buzz of motors fills the sky.
Sipping hot coffee from a Thermos, your
friend, Bill, looks on approvingly as you
make touch-and-gos across the runway
with your Sportflyer.
However, the fates are fickle today. On
the “final” pass, your model’s right wingtip
stalls and digs in, and your pretty little
ARF cartwheels down the runway like a
Romanian gymnast.
When it comes to rest, the structure is
intact but the covering is damaged from its
recent brush with the blacktop. As you
bring the pieces of the model back to the
bench, Bill asks, “So, what are you gonna
do now?”
Your answer may come down to a
decision between your wallet and your
willingness to learn new skills. You could
buy a replacement ARF; that’s your wallet
speaking. Or if willingness whispers in
your ear, you could learn to re-cover your
aircraft.
Re-covering doesn’t always follow a
crash. Other reasons to take on the task
include wear, tear, and time; normal use and
handling can necessitate such a job.
Another motive for re-covering is less
about a model’s flying qualities and more
about how many fliers don’t want their
ARFs to look like all the others. Altering the
aircraft’s appearance allows you to express
your individuality, resulting in such
compliments as, “I didn’t know that airplane
came in that color scheme.”
Tools used in the covering process are
shown in the accompanying photo and
drawing. One of the sidebars explains tool
usage and which ones are required or
optional.
Make sure you have a large, clear work
surface with good lighting—ideally from
two sides. Lay a large towel under the
covering you are working on, to help
prevent it from being scratched.
Uncovering Your ARF: Once you have
made the decision to re-cover, it is essential to
remove all of the old covering—unless you
plan on retaining the same color scheme or
redoing only a broken or punctured part, such
as a wing. If you cover only one component,
find out what brand of covering was
originally used on the model.
Matching brands will facilitate replicating
the original color. On the Carl Goldberg
Products Tiger 400 I’m using for this
exercise, the kit instructions indicate that the
covering is Cub Yellow Oracover and White
Oracover.
To remove the old covering, warm it with
a heat gun to loosen the adhesive. If you don’t
have a heat gun, you can use a covering iron.
Wear cotton gloves to protect your hands
during this job; at temperatures of up to 400°,
a heat gun can cause serious burns.
You will need to pull the covering slowly
and at an angle, to minimize residual glue
problems. Once you have the material off, use
acetone or a covering thinner such as Coverite
Ironex to remove any leftover adhesive or
stuck bits of covering.
Acetone and the toluene in Ironex are
toxic and flammable, and they can be
absorbed through the skin; wear rubber
gloves and make sure you have adequate
ventilation. Working outside on a folding
workbench covered with plastic is a safer way
to use these chemicals.
A spot remover such as K2r can be used
to remove and absorb fuel stains on a gaspowered
ARF. For extremely stubborn
covering, such as dried-on butyrate dope, I
have resorted to using paint remover. But
removing paint remover is almost more
trouble than using it.
Surface preparation and damage repair
make the final covering look better. Once you
have removed the material, you need to
inspect the model for cracked ribs, broken
spars, cracked sheet surfaces, and loose
engine and landing-gear mountings. If the
Various tools are used in the covering process. Preparation of the model is just as
important as applying the covering.
Personalize your ARF to
make it stand out
by Jon Putnam
Off With the Old,
on With
the New
February 2009 33
02sig2.QXD 12/22/08 11:01 AM Page 33
34 MODEL AVIATION
Artwork from the box or advertisement
is traced to create an isometric view of
the canvas.
Warm the old covering with a heat gun.
Wear cotton gloves for protection. Pull the
covering slowly, at an angle, to prevent
residual adhesive from sticking to the ARF.
Left: Use graph
paper with 1/4-inch
squares to estimate
materials required
to cover the model.
A p p r o x i m a t e
dimensions so that
there is enough
overhang to handle
the material.
Covering Project Tools
Surface Preparation
Name Usage Required?
Light spackle Filling small dings, scratches, cracks Small amounts are usually needed
Vinyl spackle Filling deeper gouges Small amounts are usually needed
Palette knife Applying spackle Yes (plastic knife will work)
Sanding blocks (240-320 grit) Sanding structure before covering Yes
Tack rag Removing sanding dust before covering Yes
Acetone or lacquer thinner Removing excess adhesive, small stuck bits of covering If there is excess adhesive
Rubber gloves Wearing when handling thinners If there is excess adhesive
Cutting and Measuring
Name Usage Required?
Single-edge razor blades Cutting covering: straight lines If using only X-Acto, change blades frequently
X-Acto knife with extra #11 blades Cutting covering: curves If using only X-Acto, change blades frequently
Pilot water-based fine-tip pen Marking covering during cutting Yes
Scissors Trimming small edges No
Cutting surface (synthetic cutting board, Using as cutting board Yes
glass, or Masonite; avoid wood with grain)
Steel measuring rule, straightedge: Measuring covering and cutting straight lines Yes
18- and 36-inch rules (can substitute
carpenter’s framing square)
Covering
Name Usage Required?
Iron-on film Covering the ARF Yes
Coverite Ironex Cleaning covering irons, removing excess glue Yes
Covering iron with sock Tacking, adhering covering to airplane Covering or trim iron required. If only
framework, tightening covering trim iron, heat gun is needed.
Trim iron Tacking, adhering small trim pieces to airplane Covering or trim iron required. If only
framework, tightening covering trim iron, heat gun is needed.
Extra tip for trim iron Flat, curved tips for trimming iron to fit Supplied with trim iron
appropriate surfaces
Covering thermometer Setting temperature of iron No (not needed if thermometer is built in)
Heat gun Shrinking, tightening covering (Can use only Yes
covering iron to shrink covering)
Cotton gloves Protecting hands near heat gun Yes
Cotton balls Wiping down covering, removing air Yes
Acetone or covering thinners such as
Coverite Ironex remove extremely old,
stubborn coverings or residual adhesive.
These liquids are toxic and flammable; wear
rubber gloves and have adequate ventilation.
02sig2.QXD 12/22/08 11:02 AM Page 34
Photos by the author
February 2009 35
Begin the wing by covering small items such
as this inside edge of the aileron cavity with
a trim iron. A towel under the wing helps
prevent scratches and dings.
Seam the fuselage at the nose, and then pull and form a
V back to the tail. Tack and seam down the sides,
starting in the middle at the wing saddle and the
cockpit, working out in both directions.
Use a V pattern for covering whenever possible, as
shown. Tack the inside center, and stretch tightly to
and tack and form a symmetrical V. You may have to
pull and retack.
Card-stock patterns are made for curves
that fill in this wing’s transparent
“windows.” The card pattern is transferred
onto balsa and glued to the wing.
Comparison of Iron-on Plastic Film Coverings
High-Heat Film Coverings Low-Heat Film Coverings Light Film, Microlite Film Coverings
Brands Coverite 21st Century Film, AeroKote, Coverite Black Baron AeroKote Lite, Coverite 21st Century
MonoKote, UltraCote Film, EconoKote, Polycover, Microlite, Nelson LiteFilm
Supercover, TowerKote
Recommended Models spanning 30-50 inches that Models spanning 30-50 inches with Lightweight park flyers and indoor models
for require fuel-proofing, durability, foam, covered foam, foam board, spanning less than 30 to 50 inches
structural integrity, wide color choice plastic, or with which cost is a factor
Not Recommended Foam, plastics Designs needing great strength Models with wingspans exceeding 50
for in the covering inches
Weight 1.8-2.5 1.8-2.5 0.6-1.8
(ounces/
square yard)
Heat to Affix 225°-325° 200° 135°-200°
to Wood
Heat to Shrink Up to 350°-400° Up to 250° Up to 250°
Color Range Largest Limited Limited
Weights and heats shown are approximate. Refer to a specific material’s Web site for exact weights. See the directions that come
with the material for the heat range needed to affix to wood or shrink. MA
—Jon Putnam
02sig2.QXD 12/22/08 11:03 AM Page 35
February 2009 37
In overcast conditions, light colors appear white
and dark colors go almost black.
The easiest way to attach overlapping material
and much of the other trim is to use Windex,
which makes it easy to remove air bubbles
between layers of film.
Make sure the pattern is smooth so the
knife will not hang up. Tape one side of
the pattern down to the film; keeping a
lot of pressure on the pattern, cut the
untaped side.
To finish the wings, the author used a sharp
X-Acto knife to cut 1/4-inch strips of red trim
and made cardboard patterns using a
Hobbico Circle Cutter.
The top film on the fuselage has been
added, all film is trimmed and shrunk,
and the fuselage is completely covered
with yellow film.
The Tiger 400 after all covering and trim film has been applied. Its new look maintains ease of recognition while highlighting
this ARF’s beautiful structure.
Coverite 21st Century Microlite Specifications
Size/Form Weight/Square Temperature to Temperature to Available Colors
Yard Affix to Wood Shrink
273/4 x 0.6 ounce 175°-195° 230-250° Seven opaque, four
72-inch roll transparent, Clear,
Silver
02sig2.QXD 12/22/08 11:07 AM Page 37
airplane needs repairs or regluing, now is
the time to do it.
Once you have made the repairs, fill
nicks and dings using light or vinyl
spackle and a palette knife. Lightly sand
the surface with 240- to 320-grit paper.
When you are finished sanding, wipe
off the surface with a tack rag. Run your
fingers over the surface and hold the
model up to the light at an angle to check
for imperfections. If you can feel or see
flaws now, you’ll see them later when
your ARF is covered. Covering does not
hide the bad workmanship under it.
Choosing a Covering: Before you select
the airplane’s colors, decide if you will
use opaque or transparent film, or some
combination of each, and which brands
come in the shades you want. To pick a
type and brand of covering, you need to
understand the differences between them.
Iron-on coverings come in four types:
high heat, low heat, fabric, and light films.
Fabric coverings are used mainly on
heavier scale models of full-scale
airplanes that were covered with fabric.
I’ll skip those, because the Tiger 400 is a
lightweight, nonscale ARF. An
accompanying sidebar describes the
differences between iron-on plastic films.
For the Tiger 400, I decided to use
Coverite 21st Century Microlite: a light,
iron-on plastic that is suited to airplanes
with wings spanning less than 50 inches.
A sidebar contains this material’s
specifications.
Since my model is a low-weight
electric, it does not need a heavier
covering with fuelproof qualities. And
because it is built lightly, it does not have
structures to resist the force and pull of
heavier coverings when they shrink, which
can lead to warping or breakage.
No matter what film you choose, be
aware of the size of roll it comes in, its
weight, its temperature rating, and the
colors that are available.
The Covering Method: A logical process
makes covering easier. There are four
main points to remember.
1. Start small or simple. Learn to cover
by practicing on scrap balsa or a smaller
object such as a simple wing, rudder, or
stabilizer until you have a feel for the
temperature and the tools. Tackle more
difficult items such as a fuselage later.
2. Cover bottom to top and back to
front. Imagine air and fuel running over
your ARF from front to back and top to
bottom. If a seam’s edge faces down or
back, it will be much less likely to show
when light hits it, catch air from the
slipstream, or collect fuel and dirt.
3. On a wing or stabilizer, where
possible, cover the bottom first and top
last, overlapping the top covering around
and over the bottom by 1/8 inch. On a
fuselage, cover the bottom, the sides, and
then the top. There can be exceptions,
depending on how the model is constructed.
With a two-color scheme, try to have the
darker color overlap the lighter one, or the
opaque shade overlap the transparent one.
On my Tiger 400, the Microlite White on
the front of the fuselage and the wings will
overlap the Microlite Transparent Yellow.
4. Hide seams under trim. If you are
going to apply a trim piece on the side of a
fuselage or striping to a wing, use it to hide
a seam if there is one.
On my Tiger 400, the red wing striping
hides the seam where the white overlaps the
yellow. White Microlite is not very opaque,
and some of the yellow would show through
without this trim layer.
Covering the wing and control surfaces
in two colors is not that hard. I decided to
use Transparent Yellow over the open rib
sections and opaque White on the LE, tip
wing bay, and center-section. This will
create transparent “windows” in the wing,
which improves visibility at a distance and
looks great.
If you don’t want to get involved in a
two-color job, you can follow these
directions and cover the entire bottom of the
wing and then the top. Most directions that
come with film rolls illustrate covering a
simple wing.
The Tiger 400’s design drawing shows a
curved shape for the transparent sections on
the wing. One way to achieve this is to add
small sections of balsa sheet in the shape of
the curve at both tips and the wing centersection.
Begin the wing by covering small areas
such as the inside edge of the aileron cavity.
A trim iron is ideal for these diminutive
pieces. The forward edge of the aileron
cavity will be concealed by the film from
the top and bottom of the wing.
I like to place the wing on a towel, to
avoid scratching the film when working on
it. To begin, I cut the yellow covering
according to the cutting guide. To do this,
lay the material on a cutting board with the
adhesive-side up. With transparent film, a
cutting board marked with a 1-inch grid
makes this operation a snap.
Mark the covering with a water-based
Pilot pen. Slice the film from the roll using
a steel rule and a sharp X-Acto knife or
razor blade. Remove the backing and place
the covering on the bottom of the wing.
Whenever I can, I use a “V” pattern to
attach the covering. To use this technique,
tack the inside center seam and then
stretch the film tightly to each side of the
center. Then form a symmetrical V out to
the tip. Beginning at the center of each
side, tack at roughly 1-inch intervals out to
the four corners. Once the material is
tacked, seal it to the wood.
Cut notches for the film around each
rib, seal it to the spar, and then seal it to
the TE and the center and tip of the wing
panel. Seal all edges again and then shrink
with a heat gun.
I often seal more edge than I know will
eventually remain on the model, to assist in
keeping the film attached while I heatshrink
it. I also routinely reseal film after
shrinking it with a heat gun, because the
gun can loosen the adhesive. When all this
is done, trim the panel.
Shrinking film with a heat gun is more
art than science. Try to work the entire
piece at one time, starting 3-4 inches above
it.
When using a heat gun, you can always
get closer and bring more heat into contact
with the film. If you are using a covering
iron, you can always turn up the
temperature. You can easily burn a hole in
the film if you get too close with a heat gun,
which usually means you will need to recover
that panel.
Keeping the heat gun or covering iron
moving continually across the film will help
you avoid burn holes. Shielding
neighboring film with cardboard or a wet
rag is a great tactic to avoid burning film.
Once the film is taut, rub any area on
sheet balsa with a cotton ball to work air
bubbles out and help set the glue. If there
are small creases that don’t pull out with the
heat gun, I often remove them with a trim
iron rather than risk getting too close with a
heat gun. Reseal all seams after shrinking
with a heat gun.
At this point I trim the ends of the
finished heat-shrunk yellow wing panel
using a cardboard pattern, a new X-Acto
blade, and a light touch. I apply enough
pressure to cut only the film—not the balsa
under it. I also trim the TE, leaving roughly
1/8 inch wrapped around the upper side of
the wing.
As I mentioned, the Tiger 400’s tips will
be covered in white. If you are doing a onecolor
scheme, finish the tips first so that the
wing film will overlap them. I start with the
bottom of the tip and then cover the top.
Tack the film on the high point or spar
position of the top of the end rib, and then
stretch and seal that rib to the TE. Repeat
the process for the LE. Beginning at the
same spar location, stretch the film and seal
it to the outer edges of the tip. When
finished, carefully shrink the film and trim
off the excess.
Repeat those steps for the top of the tip,
and you have one tip done. Covering these
components takes time, but the reward is
worth it.
To cover the remaining curved portions
of covering near the tip and wing center,
make a cardboard pattern to fit the space.
02sig2.QXD 12/22/08 11:08 AM Page 40
This will be almost the same shape that was
filled with sheet 1/16 balsa. Add extra film to
the uncurved edges.
To make this pattern and most of the
others, use thick poster board and a sharp
blade on the hobby knife to ensure a smooth
cut. When finished, I cut eight pieces of the
opaque white.
A trim iron comes in handy for attaching
the white panels. Keeping the seam small, I
tack at the lowest point of the curve. Then I
pull and seal the film to the TE, slightly
overlapping the yellow, and finish the curve.
I seal the center seam as well as the top
edge, smooth any wrinkles, push out air
bubbles, and close the seam at the bottom.
Shrinking the panel with a gun or iron
follows.
A delicate touch is required if you are
using a heat gun. Protect the panel next to it
with a piece of cardboard or a damp cloth,
to avoid burns. Use cotton to work out any
air bubbles. Repeat this process for all
panels. When finished, you can apply Top
Flite MonoKote Trim Solvent with a small
swab to seal the edge between the differentcolor
films.
After completing those panels, you’ll
probably find that the wing’s LE will be a
snap to cover. Of course, you’ll do the
bottom side first so that the top film
overlaps it.
The covering is attached along the spar
line. Tack it at the center, and then stretch
and seal it to the tip, taking care to keep the
line straight. Tack the LE in the center of
the wing panel, and tack and stretch at 1-
inch intervals in both directions.
When finished, all edges are sealed, the
panel is shrunk, and the excess material is
trimmed off using a straightedge. Now
cover both bottom panels and both top
panels.
At this point, my Tiger 400’s wing is
completely covered with the yellow and
white film. All that remains is to attach the
red trim.
The easiest way to attach a strip or much
of the other trim to a model is to use a
method involving Windex. It can virtually
eliminate air bubbles between layers of
film.
On my ARF, I sprayed a light coat of
the glass cleaner on the plastic, aligned the
white film where I wanted it, and used a
credit card to squeegee out the excess
liquid. I cleaned up and worked out any
remaining Windex with a tissue.
Pushing the credit card rather than
dragging it works better, and its edge can
be used quite effectively to nudge pieces of
film into place. If you have any persistent
air bubbles, prick them with a sharp pin
and work out the air. Let one side dry
overnight before doing the other side, or
you may regret it.
If the film overlaps an edge such as the
LE or TE, tack it to that edge with a trim
iron. When the film is dry, you can use
extremely low heat on a covering iron to
set the adhesive in the trim film and then
seal the edges with trim solvent. If a piece
does not look right when dried, it can
usually be lifted, sprayed, and repositioned.
To finish my ARF’s wings, I used an
incredibly sharp X-Acto knife to cut 1/4
inch of red trim from film in strips and
curves. The cardboard patterns for the
curves were easy to make with help from a
Hobbico Circle Cutter. I applied all the red
trim using Windex, set the adhesive with an
iron on low heat, and then sealed it using
trim solvent.
One of the hardest things to do is cut out
small trim pieces, such as the 1/4-inch-wide
curves for the red trim, and get a smooth
cut. I use the following tips for success.
Use a new, sharp X-Acto blade. Make
sure the pattern is smooth so that the knife
blade will not hang up on it. Tape one side
of the pattern down and, while keeping
pressure on it, cut the untaped edge in one
smooth, continuous motion. Without
moving the pattern, apply tape to the other
side of the pattern, remove the original
tape, and cut the remaining side. When
designing these curved pieces, allow extra
film to overlap the adjoining piece.
I decided to deviate from the plan and
add 1/8-inch red Great Planes Kwik Stripe
Striping Tape on top of the white side
stripe and 1/16-inch white tape along the
back edge of the tail surfaces, to echo the
line I formed on the wings.
I had not planned on using the red side
stripe; however, once the Tiger 400 was
finished, I felt like it needed one more
stripe to complete the trim scheme.
Striping tape was a fast and easy way to
obtain it.
Anyone can learn to cover a model. The
results can be rewarding and give your
airplane that custom, non-ARF look that
will set it apart at the flying field. As I did,
you might also gain an appreciation of how
good the work is that comes out of the
ARF factories.
Good covering and happy flying! MA
Jon Putnam
[email protected]
That was only part of the covering job;
there’s still a fuselage and a tail section to
do. You can find that part of the story and
many more photos on MA’s Sport Aviator
Web site.
—MA Staff
Sources:
Tiger 400 review, Jon Putnam’s complete
covering how-to:
Sport Aviator
www.masportaviator.com
Radio Control Model Airplanes (book) by
John Carroll:
Kalmbach Books
(800) 533-6644
www.kalmbach.com
There Are No Secrets (book) by Harry
Higley, Tom’s Techniques (book) by Tom
Ingram and Harry Higley:
Harry B. Higley & Sons, Inc.
433 W. Arquilla Dr.
Glenwood IL 60425
www.harryhigley.com
Covering RC Airplanes: Volume I (book) by
Faye Stilley, Covering RC Airplanes:
Volume II (book) by Faye Stilley:
RCStore.com
(888) 235-2021
https://secure.rcstore.com

IMAGINE THAT you’re at the flying field
at 10 a.m. on a bluebird-fine Saturday
morning. There are clear skies with no wind,
and the happy buzz of motors fills the sky.
Sipping hot coffee from a Thermos, your
friend, Bill, looks on approvingly as you
make touch-and-gos across the runway
with your Sportflyer.
However, the fates are fickle today. On
the “final” pass, your model’s right wingtip
stalls and digs in, and your pretty little
ARF cartwheels down the runway like a
Romanian gymnast.
When it comes to rest, the structure is
intact but the covering is damaged from its
recent brush with the blacktop. As you
bring the pieces of the model back to the
bench, Bill asks, “So, what are you gonna
do now?”
Your answer may come down to a
decision between your wallet and your
willingness to learn new skills. You could
buy a replacement ARF; that’s your wallet
speaking. Or if willingness whispers in
your ear, you could learn to re-cover your
aircraft.
Re-covering doesn’t always follow a
crash. Other reasons to take on the task
include wear, tear, and time; normal use and
handling can necessitate such a job.
Another motive for re-covering is less
about a model’s flying qualities and more
about how many fliers don’t want their
ARFs to look like all the others. Altering the
aircraft’s appearance allows you to express
your individuality, resulting in such
compliments as, “I didn’t know that airplane
came in that color scheme.”
Tools used in the covering process are
shown in the accompanying photo and
drawing. One of the sidebars explains tool
usage and which ones are required or
optional.
Make sure you have a large, clear work
surface with good lighting—ideally from
two sides. Lay a large towel under the
covering you are working on, to help
prevent it from being scratched.
Uncovering Your ARF: Once you have
made the decision to re-cover, it is essential to
remove all of the old covering—unless you
plan on retaining the same color scheme or
redoing only a broken or punctured part, such
as a wing. If you cover only one component,
find out what brand of covering was
originally used on the model.
Matching brands will facilitate replicating
the original color. On the Carl Goldberg
Products Tiger 400 I’m using for this
exercise, the kit instructions indicate that the
covering is Cub Yellow Oracover and White
Oracover.
To remove the old covering, warm it with
a heat gun to loosen the adhesive. If you don’t
have a heat gun, you can use a covering iron.
Wear cotton gloves to protect your hands
during this job; at temperatures of up to 400°,
a heat gun can cause serious burns.
You will need to pull the covering slowly
and at an angle, to minimize residual glue
problems. Once you have the material off, use
acetone or a covering thinner such as Coverite
Ironex to remove any leftover adhesive or
stuck bits of covering.
Acetone and the toluene in Ironex are
toxic and flammable, and they can be
absorbed through the skin; wear rubber
gloves and make sure you have adequate
ventilation. Working outside on a folding
workbench covered with plastic is a safer way
to use these chemicals.
A spot remover such as K2r can be used
to remove and absorb fuel stains on a gaspowered
ARF. For extremely stubborn
covering, such as dried-on butyrate dope, I
have resorted to using paint remover. But
removing paint remover is almost more
trouble than using it.
Surface preparation and damage repair
make the final covering look better. Once you
have removed the material, you need to
inspect the model for cracked ribs, broken
spars, cracked sheet surfaces, and loose
engine and landing-gear mountings. If the
Various tools are used in the covering process. Preparation of the model is just as
important as applying the covering.
Personalize your ARF to
make it stand out
by Jon Putnam
Off With the Old,
on With
the New
February 2009 33
02sig2.QXD 12/22/08 11:01 AM Page 33
34 MODEL AVIATION
Artwork from the box or advertisement
is traced to create an isometric view of
the canvas.
Warm the old covering with a heat gun.
Wear cotton gloves for protection. Pull the
covering slowly, at an angle, to prevent
residual adhesive from sticking to the ARF.
Left: Use graph
paper with 1/4-inch
squares to estimate
materials required
to cover the model.
A p p r o x i m a t e
dimensions so that
there is enough
overhang to handle
the material.
Covering Project Tools
Surface Preparation
Name Usage Required?
Light spackle Filling small dings, scratches, cracks Small amounts are usually needed
Vinyl spackle Filling deeper gouges Small amounts are usually needed
Palette knife Applying spackle Yes (plastic knife will work)
Sanding blocks (240-320 grit) Sanding structure before covering Yes
Tack rag Removing sanding dust before covering Yes
Acetone or lacquer thinner Removing excess adhesive, small stuck bits of covering If there is excess adhesive
Rubber gloves Wearing when handling thinners If there is excess adhesive
Cutting and Measuring
Name Usage Required?
Single-edge razor blades Cutting covering: straight lines If using only X-Acto, change blades frequently
X-Acto knife with extra #11 blades Cutting covering: curves If using only X-Acto, change blades frequently
Pilot water-based fine-tip pen Marking covering during cutting Yes
Scissors Trimming small edges No
Cutting surface (synthetic cutting board, Using as cutting board Yes
glass, or Masonite; avoid wood with grain)
Steel measuring rule, straightedge: Measuring covering and cutting straight lines Yes
18- and 36-inch rules (can substitute
carpenter’s framing square)
Covering
Name Usage Required?
Iron-on film Covering the ARF Yes
Coverite Ironex Cleaning covering irons, removing excess glue Yes
Covering iron with sock Tacking, adhering covering to airplane Covering or trim iron required. If only
framework, tightening covering trim iron, heat gun is needed.
Trim iron Tacking, adhering small trim pieces to airplane Covering or trim iron required. If only
framework, tightening covering trim iron, heat gun is needed.
Extra tip for trim iron Flat, curved tips for trimming iron to fit Supplied with trim iron
appropriate surfaces
Covering thermometer Setting temperature of iron No (not needed if thermometer is built in)
Heat gun Shrinking, tightening covering (Can use only Yes
covering iron to shrink covering)
Cotton gloves Protecting hands near heat gun Yes
Cotton balls Wiping down covering, removing air Yes
Acetone or covering thinners such as
Coverite Ironex remove extremely old,
stubborn coverings or residual adhesive.
These liquids are toxic and flammable; wear
rubber gloves and have adequate ventilation.
02sig2.QXD 12/22/08 11:02 AM Page 34
Photos by the author
February 2009 35
Begin the wing by covering small items such
as this inside edge of the aileron cavity with
a trim iron. A towel under the wing helps
prevent scratches and dings.
Seam the fuselage at the nose, and then pull and form a
V back to the tail. Tack and seam down the sides,
starting in the middle at the wing saddle and the
cockpit, working out in both directions.
Use a V pattern for covering whenever possible, as
shown. Tack the inside center, and stretch tightly to
and tack and form a symmetrical V. You may have to
pull and retack.
Card-stock patterns are made for curves
that fill in this wing’s transparent
“windows.” The card pattern is transferred
onto balsa and glued to the wing.
Comparison of Iron-on Plastic Film Coverings
High-Heat Film Coverings Low-Heat Film Coverings Light Film, Microlite Film Coverings
Brands Coverite 21st Century Film, AeroKote, Coverite Black Baron AeroKote Lite, Coverite 21st Century
MonoKote, UltraCote Film, EconoKote, Polycover, Microlite, Nelson LiteFilm
Supercover, TowerKote
Recommended Models spanning 30-50 inches that Models spanning 30-50 inches with Lightweight park flyers and indoor models
for require fuel-proofing, durability, foam, covered foam, foam board, spanning less than 30 to 50 inches
structural integrity, wide color choice plastic, or with which cost is a factor
Not Recommended Foam, plastics Designs needing great strength Models with wingspans exceeding 50
for in the covering inches
Weight 1.8-2.5 1.8-2.5 0.6-1.8
(ounces/
square yard)
Heat to Affix 225°-325° 200° 135°-200°
to Wood
Heat to Shrink Up to 350°-400° Up to 250° Up to 250°
Color Range Largest Limited Limited
Weights and heats shown are approximate. Refer to a specific material’s Web site for exact weights. See the directions that come
with the material for the heat range needed to affix to wood or shrink. MA
—Jon Putnam
02sig2.QXD 12/22/08 11:03 AM Page 35
February 2009 37
In overcast conditions, light colors appear white
and dark colors go almost black.
The easiest way to attach overlapping material
and much of the other trim is to use Windex,
which makes it easy to remove air bubbles
between layers of film.
Make sure the pattern is smooth so the
knife will not hang up. Tape one side of
the pattern down to the film; keeping a
lot of pressure on the pattern, cut the
untaped side.
To finish the wings, the author used a sharp
X-Acto knife to cut 1/4-inch strips of red trim
and made cardboard patterns using a
Hobbico Circle Cutter.
The top film on the fuselage has been
added, all film is trimmed and shrunk,
and the fuselage is completely covered
with yellow film.
The Tiger 400 after all covering and trim film has been applied. Its new look maintains ease of recognition while highlighting
this ARF’s beautiful structure.
Coverite 21st Century Microlite Specifications
Size/Form Weight/Square Temperature to Temperature to Available Colors
Yard Affix to Wood Shrink
273/4 x 0.6 ounce 175°-195° 230-250° Seven opaque, four
72-inch roll transparent, Clear,
Silver
02sig2.QXD 12/22/08 11:07 AM Page 37
airplane needs repairs or regluing, now is
the time to do it.
Once you have made the repairs, fill
nicks and dings using light or vinyl
spackle and a palette knife. Lightly sand
the surface with 240- to 320-grit paper.
When you are finished sanding, wipe
off the surface with a tack rag. Run your
fingers over the surface and hold the
model up to the light at an angle to check
for imperfections. If you can feel or see
flaws now, you’ll see them later when
your ARF is covered. Covering does not
hide the bad workmanship under it.
Choosing a Covering: Before you select
the airplane’s colors, decide if you will
use opaque or transparent film, or some
combination of each, and which brands
come in the shades you want. To pick a
type and brand of covering, you need to
understand the differences between them.
Iron-on coverings come in four types:
high heat, low heat, fabric, and light films.
Fabric coverings are used mainly on
heavier scale models of full-scale
airplanes that were covered with fabric.
I’ll skip those, because the Tiger 400 is a
lightweight, nonscale ARF. An
accompanying sidebar describes the
differences between iron-on plastic films.
For the Tiger 400, I decided to use
Coverite 21st Century Microlite: a light,
iron-on plastic that is suited to airplanes
with wings spanning less than 50 inches.
A sidebar contains this material’s
specifications.
Since my model is a low-weight
electric, it does not need a heavier
covering with fuelproof qualities. And
because it is built lightly, it does not have
structures to resist the force and pull of
heavier coverings when they shrink, which
can lead to warping or breakage.
No matter what film you choose, be
aware of the size of roll it comes in, its
weight, its temperature rating, and the
colors that are available.
The Covering Method: A logical process
makes covering easier. There are four
main points to remember.
1. Start small or simple. Learn to cover
by practicing on scrap balsa or a smaller
object such as a simple wing, rudder, or
stabilizer until you have a feel for the
temperature and the tools. Tackle more
difficult items such as a fuselage later.
2. Cover bottom to top and back to
front. Imagine air and fuel running over
your ARF from front to back and top to
bottom. If a seam’s edge faces down or
back, it will be much less likely to show
when light hits it, catch air from the
slipstream, or collect fuel and dirt.
3. On a wing or stabilizer, where
possible, cover the bottom first and top
last, overlapping the top covering around
and over the bottom by 1/8 inch. On a
fuselage, cover the bottom, the sides, and
then the top. There can be exceptions,
depending on how the model is constructed.
With a two-color scheme, try to have the
darker color overlap the lighter one, or the
opaque shade overlap the transparent one.
On my Tiger 400, the Microlite White on
the front of the fuselage and the wings will
overlap the Microlite Transparent Yellow.
4. Hide seams under trim. If you are
going to apply a trim piece on the side of a
fuselage or striping to a wing, use it to hide
a seam if there is one.
On my Tiger 400, the red wing striping
hides the seam where the white overlaps the
yellow. White Microlite is not very opaque,
and some of the yellow would show through
without this trim layer.
Covering the wing and control surfaces
in two colors is not that hard. I decided to
use Transparent Yellow over the open rib
sections and opaque White on the LE, tip
wing bay, and center-section. This will
create transparent “windows” in the wing,
which improves visibility at a distance and
looks great.
If you don’t want to get involved in a
two-color job, you can follow these
directions and cover the entire bottom of the
wing and then the top. Most directions that
come with film rolls illustrate covering a
simple wing.
The Tiger 400’s design drawing shows a
curved shape for the transparent sections on
the wing. One way to achieve this is to add
small sections of balsa sheet in the shape of
the curve at both tips and the wing centersection.
Begin the wing by covering small areas
such as the inside edge of the aileron cavity.
A trim iron is ideal for these diminutive
pieces. The forward edge of the aileron
cavity will be concealed by the film from
the top and bottom of the wing.
I like to place the wing on a towel, to
avoid scratching the film when working on
it. To begin, I cut the yellow covering
according to the cutting guide. To do this,
lay the material on a cutting board with the
adhesive-side up. With transparent film, a
cutting board marked with a 1-inch grid
makes this operation a snap.
Mark the covering with a water-based
Pilot pen. Slice the film from the roll using
a steel rule and a sharp X-Acto knife or
razor blade. Remove the backing and place
the covering on the bottom of the wing.
Whenever I can, I use a “V” pattern to
attach the covering. To use this technique,
tack the inside center seam and then
stretch the film tightly to each side of the
center. Then form a symmetrical V out to
the tip. Beginning at the center of each
side, tack at roughly 1-inch intervals out to
the four corners. Once the material is
tacked, seal it to the wood.
Cut notches for the film around each
rib, seal it to the spar, and then seal it to
the TE and the center and tip of the wing
panel. Seal all edges again and then shrink
with a heat gun.
I often seal more edge than I know will
eventually remain on the model, to assist in
keeping the film attached while I heatshrink
it. I also routinely reseal film after
shrinking it with a heat gun, because the
gun can loosen the adhesive. When all this
is done, trim the panel.
Shrinking film with a heat gun is more
art than science. Try to work the entire
piece at one time, starting 3-4 inches above
it.
When using a heat gun, you can always
get closer and bring more heat into contact
with the film. If you are using a covering
iron, you can always turn up the
temperature. You can easily burn a hole in
the film if you get too close with a heat gun,
which usually means you will need to recover
that panel.
Keeping the heat gun or covering iron
moving continually across the film will help
you avoid burn holes. Shielding
neighboring film with cardboard or a wet
rag is a great tactic to avoid burning film.
Once the film is taut, rub any area on
sheet balsa with a cotton ball to work air
bubbles out and help set the glue. If there
are small creases that don’t pull out with the
heat gun, I often remove them with a trim
iron rather than risk getting too close with a
heat gun. Reseal all seams after shrinking
with a heat gun.
At this point I trim the ends of the
finished heat-shrunk yellow wing panel
using a cardboard pattern, a new X-Acto
blade, and a light touch. I apply enough
pressure to cut only the film—not the balsa
under it. I also trim the TE, leaving roughly
1/8 inch wrapped around the upper side of
the wing.
As I mentioned, the Tiger 400’s tips will
be covered in white. If you are doing a onecolor
scheme, finish the tips first so that the
wing film will overlap them. I start with the
bottom of the tip and then cover the top.
Tack the film on the high point or spar
position of the top of the end rib, and then
stretch and seal that rib to the TE. Repeat
the process for the LE. Beginning at the
same spar location, stretch the film and seal
it to the outer edges of the tip. When
finished, carefully shrink the film and trim
off the excess.
Repeat those steps for the top of the tip,
and you have one tip done. Covering these
components takes time, but the reward is
worth it.
To cover the remaining curved portions
of covering near the tip and wing center,
make a cardboard pattern to fit the space.
02sig2.QXD 12/22/08 11:08 AM Page 40
This will be almost the same shape that was
filled with sheet 1/16 balsa. Add extra film to
the uncurved edges.
To make this pattern and most of the
others, use thick poster board and a sharp
blade on the hobby knife to ensure a smooth
cut. When finished, I cut eight pieces of the
opaque white.
A trim iron comes in handy for attaching
the white panels. Keeping the seam small, I
tack at the lowest point of the curve. Then I
pull and seal the film to the TE, slightly
overlapping the yellow, and finish the curve.
I seal the center seam as well as the top
edge, smooth any wrinkles, push out air
bubbles, and close the seam at the bottom.
Shrinking the panel with a gun or iron
follows.
A delicate touch is required if you are
using a heat gun. Protect the panel next to it
with a piece of cardboard or a damp cloth,
to avoid burns. Use cotton to work out any
air bubbles. Repeat this process for all
panels. When finished, you can apply Top
Flite MonoKote Trim Solvent with a small
swab to seal the edge between the differentcolor
films.
After completing those panels, you’ll
probably find that the wing’s LE will be a
snap to cover. Of course, you’ll do the
bottom side first so that the top film
overlaps it.
The covering is attached along the spar
line. Tack it at the center, and then stretch
and seal it to the tip, taking care to keep the
line straight. Tack the LE in the center of
the wing panel, and tack and stretch at 1-
inch intervals in both directions.
When finished, all edges are sealed, the
panel is shrunk, and the excess material is
trimmed off using a straightedge. Now
cover both bottom panels and both top
panels.
At this point, my Tiger 400’s wing is
completely covered with the yellow and
white film. All that remains is to attach the
red trim.
The easiest way to attach a strip or much
of the other trim to a model is to use a
method involving Windex. It can virtually
eliminate air bubbles between layers of
film.
On my ARF, I sprayed a light coat of
the glass cleaner on the plastic, aligned the
white film where I wanted it, and used a
credit card to squeegee out the excess
liquid. I cleaned up and worked out any
remaining Windex with a tissue.
Pushing the credit card rather than
dragging it works better, and its edge can
be used quite effectively to nudge pieces of
film into place. If you have any persistent
air bubbles, prick them with a sharp pin
and work out the air. Let one side dry
overnight before doing the other side, or
you may regret it.
If the film overlaps an edge such as the
LE or TE, tack it to that edge with a trim
iron. When the film is dry, you can use
extremely low heat on a covering iron to
set the adhesive in the trim film and then
seal the edges with trim solvent. If a piece
does not look right when dried, it can
usually be lifted, sprayed, and repositioned.
To finish my ARF’s wings, I used an
incredibly sharp X-Acto knife to cut 1/4
inch of red trim from film in strips and
curves. The cardboard patterns for the
curves were easy to make with help from a
Hobbico Circle Cutter. I applied all the red
trim using Windex, set the adhesive with an
iron on low heat, and then sealed it using
trim solvent.
One of the hardest things to do is cut out
small trim pieces, such as the 1/4-inch-wide
curves for the red trim, and get a smooth
cut. I use the following tips for success.
Use a new, sharp X-Acto blade. Make
sure the pattern is smooth so that the knife
blade will not hang up on it. Tape one side
of the pattern down and, while keeping
pressure on it, cut the untaped edge in one
smooth, continuous motion. Without
moving the pattern, apply tape to the other
side of the pattern, remove the original
tape, and cut the remaining side. When
designing these curved pieces, allow extra
film to overlap the adjoining piece.
I decided to deviate from the plan and
add 1/8-inch red Great Planes Kwik Stripe
Striping Tape on top of the white side
stripe and 1/16-inch white tape along the
back edge of the tail surfaces, to echo the
line I formed on the wings.
I had not planned on using the red side
stripe; however, once the Tiger 400 was
finished, I felt like it needed one more
stripe to complete the trim scheme.
Striping tape was a fast and easy way to
obtain it.
Anyone can learn to cover a model. The
results can be rewarding and give your
airplane that custom, non-ARF look that
will set it apart at the flying field. As I did,
you might also gain an appreciation of how
good the work is that comes out of the
ARF factories.
Good covering and happy flying! MA
Jon Putnam
[email protected]
That was only part of the covering job;
there’s still a fuselage and a tail section to
do. You can find that part of the story and
many more photos on MA’s Sport Aviator
Web site.
—MA Staff
Sources:
Tiger 400 review, Jon Putnam’s complete
covering how-to:
Sport Aviator
www.masportaviator.com
Radio Control Model Airplanes (book) by
John Carroll:
Kalmbach Books
(800) 533-6644
www.kalmbach.com
There Are No Secrets (book) by Harry
Higley, Tom’s Techniques (book) by Tom
Ingram and Harry Higley:
Harry B. Higley & Sons, Inc.
433 W. Arquilla Dr.
Glenwood IL 60425
www.harryhigley.com
Covering RC Airplanes: Volume I (book) by
Faye Stilley, Covering RC Airplanes:
Volume II (book) by Faye Stilley:
RCStore.com
(888) 235-2021
https://secure.rcstore.com

IMAGINE THAT you’re at the flying field
at 10 a.m. on a bluebird-fine Saturday
morning. There are clear skies with no wind,
and the happy buzz of motors fills the sky.
Sipping hot coffee from a Thermos, your
friend, Bill, looks on approvingly as you
make touch-and-gos across the runway
with your Sportflyer.
However, the fates are fickle today. On
the “final” pass, your model’s right wingtip
stalls and digs in, and your pretty little
ARF cartwheels down the runway like a
Romanian gymnast.
When it comes to rest, the structure is
intact but the covering is damaged from its
recent brush with the blacktop. As you
bring the pieces of the model back to the
bench, Bill asks, “So, what are you gonna
do now?”
Your answer may come down to a
decision between your wallet and your
willingness to learn new skills. You could
buy a replacement ARF; that’s your wallet
speaking. Or if willingness whispers in
your ear, you could learn to re-cover your
aircraft.
Re-covering doesn’t always follow a
crash. Other reasons to take on the task
include wear, tear, and time; normal use and
handling can necessitate such a job.
Another motive for re-covering is less
about a model’s flying qualities and more
about how many fliers don’t want their
ARFs to look like all the others. Altering the
aircraft’s appearance allows you to express
your individuality, resulting in such
compliments as, “I didn’t know that airplane
came in that color scheme.”
Tools used in the covering process are
shown in the accompanying photo and
drawing. One of the sidebars explains tool
usage and which ones are required or
optional.
Make sure you have a large, clear work
surface with good lighting—ideally from
two sides. Lay a large towel under the
covering you are working on, to help
prevent it from being scratched.
Uncovering Your ARF: Once you have
made the decision to re-cover, it is essential to
remove all of the old covering—unless you
plan on retaining the same color scheme or
redoing only a broken or punctured part, such
as a wing. If you cover only one component,
find out what brand of covering was
originally used on the model.
Matching brands will facilitate replicating
the original color. On the Carl Goldberg
Products Tiger 400 I’m using for this
exercise, the kit instructions indicate that the
covering is Cub Yellow Oracover and White
Oracover.
To remove the old covering, warm it with
a heat gun to loosen the adhesive. If you don’t
have a heat gun, you can use a covering iron.
Wear cotton gloves to protect your hands
during this job; at temperatures of up to 400°,
a heat gun can cause serious burns.
You will need to pull the covering slowly
and at an angle, to minimize residual glue
problems. Once you have the material off, use
acetone or a covering thinner such as Coverite
Ironex to remove any leftover adhesive or
stuck bits of covering.
Acetone and the toluene in Ironex are
toxic and flammable, and they can be
absorbed through the skin; wear rubber
gloves and make sure you have adequate
ventilation. Working outside on a folding
workbench covered with plastic is a safer way
to use these chemicals.
A spot remover such as K2r can be used
to remove and absorb fuel stains on a gaspowered
ARF. For extremely stubborn
covering, such as dried-on butyrate dope, I
have resorted to using paint remover. But
removing paint remover is almost more
trouble than using it.
Surface preparation and damage repair
make the final covering look better. Once you
have removed the material, you need to
inspect the model for cracked ribs, broken
spars, cracked sheet surfaces, and loose
engine and landing-gear mountings. If the
Various tools are used in the covering process. Preparation of the model is just as
important as applying the covering.
Personalize your ARF to
make it stand out
by Jon Putnam
Off With the Old,
on With
the New
February 2009 33
02sig2.QXD 12/22/08 11:01 AM Page 33
34 MODEL AVIATION
Artwork from the box or advertisement
is traced to create an isometric view of
the canvas.
Warm the old covering with a heat gun.
Wear cotton gloves for protection. Pull the
covering slowly, at an angle, to prevent
residual adhesive from sticking to the ARF.
Left: Use graph
paper with 1/4-inch
squares to estimate
materials required
to cover the model.
A p p r o x i m a t e
dimensions so that
there is enough
overhang to handle
the material.
Covering Project Tools
Surface Preparation
Name Usage Required?
Light spackle Filling small dings, scratches, cracks Small amounts are usually needed
Vinyl spackle Filling deeper gouges Small amounts are usually needed
Palette knife Applying spackle Yes (plastic knife will work)
Sanding blocks (240-320 grit) Sanding structure before covering Yes
Tack rag Removing sanding dust before covering Yes
Acetone or lacquer thinner Removing excess adhesive, small stuck bits of covering If there is excess adhesive
Rubber gloves Wearing when handling thinners If there is excess adhesive
Cutting and Measuring
Name Usage Required?
Single-edge razor blades Cutting covering: straight lines If using only X-Acto, change blades frequently
X-Acto knife with extra #11 blades Cutting covering: curves If using only X-Acto, change blades frequently
Pilot water-based fine-tip pen Marking covering during cutting Yes
Scissors Trimming small edges No
Cutting surface (synthetic cutting board, Using as cutting board Yes
glass, or Masonite; avoid wood with grain)
Steel measuring rule, straightedge: Measuring covering and cutting straight lines Yes
18- and 36-inch rules (can substitute
carpenter’s framing square)
Covering
Name Usage Required?
Iron-on film Covering the ARF Yes
Coverite Ironex Cleaning covering irons, removing excess glue Yes
Covering iron with sock Tacking, adhering covering to airplane Covering or trim iron required. If only
framework, tightening covering trim iron, heat gun is needed.
Trim iron Tacking, adhering small trim pieces to airplane Covering or trim iron required. If only
framework, tightening covering trim iron, heat gun is needed.
Extra tip for trim iron Flat, curved tips for trimming iron to fit Supplied with trim iron
appropriate surfaces
Covering thermometer Setting temperature of iron No (not needed if thermometer is built in)
Heat gun Shrinking, tightening covering (Can use only Yes
covering iron to shrink covering)
Cotton gloves Protecting hands near heat gun Yes
Cotton balls Wiping down covering, removing air Yes
Acetone or covering thinners such as
Coverite Ironex remove extremely old,
stubborn coverings or residual adhesive.
These liquids are toxic and flammable; wear
rubber gloves and have adequate ventilation.
02sig2.QXD 12/22/08 11:02 AM Page 34
Photos by the author
February 2009 35
Begin the wing by covering small items such
as this inside edge of the aileron cavity with
a trim iron. A towel under the wing helps
prevent scratches and dings.
Seam the fuselage at the nose, and then pull and form a
V back to the tail. Tack and seam down the sides,
starting in the middle at the wing saddle and the
cockpit, working out in both directions.
Use a V pattern for covering whenever possible, as
shown. Tack the inside center, and stretch tightly to
and tack and form a symmetrical V. You may have to
pull and retack.
Card-stock patterns are made for curves
that fill in this wing’s transparent
“windows.” The card pattern is transferred
onto balsa and glued to the wing.
Comparison of Iron-on Plastic Film Coverings
High-Heat Film Coverings Low-Heat Film Coverings Light Film, Microlite Film Coverings
Brands Coverite 21st Century Film, AeroKote, Coverite Black Baron AeroKote Lite, Coverite 21st Century
MonoKote, UltraCote Film, EconoKote, Polycover, Microlite, Nelson LiteFilm
Supercover, TowerKote
Recommended Models spanning 30-50 inches that Models spanning 30-50 inches with Lightweight park flyers and indoor models
for require fuel-proofing, durability, foam, covered foam, foam board, spanning less than 30 to 50 inches
structural integrity, wide color choice plastic, or with which cost is a factor
Not Recommended Foam, plastics Designs needing great strength Models with wingspans exceeding 50
for in the covering inches
Weight 1.8-2.5 1.8-2.5 0.6-1.8
(ounces/
square yard)
Heat to Affix 225°-325° 200° 135°-200°
to Wood
Heat to Shrink Up to 350°-400° Up to 250° Up to 250°
Color Range Largest Limited Limited
Weights and heats shown are approximate. Refer to a specific material’s Web site for exact weights. See the directions that come
with the material for the heat range needed to affix to wood or shrink. MA
—Jon Putnam
02sig2.QXD 12/22/08 11:03 AM Page 35
February 2009 37
In overcast conditions, light colors appear white
and dark colors go almost black.
The easiest way to attach overlapping material
and much of the other trim is to use Windex,
which makes it easy to remove air bubbles
between layers of film.
Make sure the pattern is smooth so the
knife will not hang up. Tape one side of
the pattern down to the film; keeping a
lot of pressure on the pattern, cut the
untaped side.
To finish the wings, the author used a sharp
X-Acto knife to cut 1/4-inch strips of red trim
and made cardboard patterns using a
Hobbico Circle Cutter.
The top film on the fuselage has been
added, all film is trimmed and shrunk,
and the fuselage is completely covered
with yellow film.
The Tiger 400 after all covering and trim film has been applied. Its new look maintains ease of recognition while highlighting
this ARF’s beautiful structure.
Coverite 21st Century Microlite Specifications
Size/Form Weight/Square Temperature to Temperature to Available Colors
Yard Affix to Wood Shrink
273/4 x 0.6 ounce 175°-195° 230-250° Seven opaque, four
72-inch roll transparent, Clear,
Silver
02sig2.QXD 12/22/08 11:07 AM Page 37
airplane needs repairs or regluing, now is
the time to do it.
Once you have made the repairs, fill
nicks and dings using light or vinyl
spackle and a palette knife. Lightly sand
the surface with 240- to 320-grit paper.
When you are finished sanding, wipe
off the surface with a tack rag. Run your
fingers over the surface and hold the
model up to the light at an angle to check
for imperfections. If you can feel or see
flaws now, you’ll see them later when
your ARF is covered. Covering does not
hide the bad workmanship under it.
Choosing a Covering: Before you select
the airplane’s colors, decide if you will
use opaque or transparent film, or some
combination of each, and which brands
come in the shades you want. To pick a
type and brand of covering, you need to
understand the differences between them.
Iron-on coverings come in four types:
high heat, low heat, fabric, and light films.
Fabric coverings are used mainly on
heavier scale models of full-scale
airplanes that were covered with fabric.
I’ll skip those, because the Tiger 400 is a
lightweight, nonscale ARF. An
accompanying sidebar describes the
differences between iron-on plastic films.
For the Tiger 400, I decided to use
Coverite 21st Century Microlite: a light,
iron-on plastic that is suited to airplanes
with wings spanning less than 50 inches.
A sidebar contains this material’s
specifications.
Since my model is a low-weight
electric, it does not need a heavier
covering with fuelproof qualities. And
because it is built lightly, it does not have
structures to resist the force and pull of
heavier coverings when they shrink, which
can lead to warping or breakage.
No matter what film you choose, be
aware of the size of roll it comes in, its
weight, its temperature rating, and the
colors that are available.
The Covering Method: A logical process
makes covering easier. There are four
main points to remember.
1. Start small or simple. Learn to cover
by practicing on scrap balsa or a smaller
object such as a simple wing, rudder, or
stabilizer until you have a feel for the
temperature and the tools. Tackle more
difficult items such as a fuselage later.
2. Cover bottom to top and back to
front. Imagine air and fuel running over
your ARF from front to back and top to
bottom. If a seam’s edge faces down or
back, it will be much less likely to show
when light hits it, catch air from the
slipstream, or collect fuel and dirt.
3. On a wing or stabilizer, where
possible, cover the bottom first and top
last, overlapping the top covering around
and over the bottom by 1/8 inch. On a
fuselage, cover the bottom, the sides, and
then the top. There can be exceptions,
depending on how the model is constructed.
With a two-color scheme, try to have the
darker color overlap the lighter one, or the
opaque shade overlap the transparent one.
On my Tiger 400, the Microlite White on
the front of the fuselage and the wings will
overlap the Microlite Transparent Yellow.
4. Hide seams under trim. If you are
going to apply a trim piece on the side of a
fuselage or striping to a wing, use it to hide
a seam if there is one.
On my Tiger 400, the red wing striping
hides the seam where the white overlaps the
yellow. White Microlite is not very opaque,
and some of the yellow would show through
without this trim layer.
Covering the wing and control surfaces
in two colors is not that hard. I decided to
use Transparent Yellow over the open rib
sections and opaque White on the LE, tip
wing bay, and center-section. This will
create transparent “windows” in the wing,
which improves visibility at a distance and
looks great.
If you don’t want to get involved in a
two-color job, you can follow these
directions and cover the entire bottom of the
wing and then the top. Most directions that
come with film rolls illustrate covering a
simple wing.
The Tiger 400’s design drawing shows a
curved shape for the transparent sections on
the wing. One way to achieve this is to add
small sections of balsa sheet in the shape of
the curve at both tips and the wing centersection.
Begin the wing by covering small areas
such as the inside edge of the aileron cavity.
A trim iron is ideal for these diminutive
pieces. The forward edge of the aileron
cavity will be concealed by the film from
the top and bottom of the wing.
I like to place the wing on a towel, to
avoid scratching the film when working on
it. To begin, I cut the yellow covering
according to the cutting guide. To do this,
lay the material on a cutting board with the
adhesive-side up. With transparent film, a
cutting board marked with a 1-inch grid
makes this operation a snap.
Mark the covering with a water-based
Pilot pen. Slice the film from the roll using
a steel rule and a sharp X-Acto knife or
razor blade. Remove the backing and place
the covering on the bottom of the wing.
Whenever I can, I use a “V” pattern to
attach the covering. To use this technique,
tack the inside center seam and then
stretch the film tightly to each side of the
center. Then form a symmetrical V out to
the tip. Beginning at the center of each
side, tack at roughly 1-inch intervals out to
the four corners. Once the material is
tacked, seal it to the wood.
Cut notches for the film around each
rib, seal it to the spar, and then seal it to
the TE and the center and tip of the wing
panel. Seal all edges again and then shrink
with a heat gun.
I often seal more edge than I know will
eventually remain on the model, to assist in
keeping the film attached while I heatshrink
it. I also routinely reseal film after
shrinking it with a heat gun, because the
gun can loosen the adhesive. When all this
is done, trim the panel.
Shrinking film with a heat gun is more
art than science. Try to work the entire
piece at one time, starting 3-4 inches above
it.
When using a heat gun, you can always
get closer and bring more heat into contact
with the film. If you are using a covering
iron, you can always turn up the
temperature. You can easily burn a hole in
the film if you get too close with a heat gun,
which usually means you will need to recover
that panel.
Keeping the heat gun or covering iron
moving continually across the film will help
you avoid burn holes. Shielding
neighboring film with cardboard or a wet
rag is a great tactic to avoid burning film.
Once the film is taut, rub any area on
sheet balsa with a cotton ball to work air
bubbles out and help set the glue. If there
are small creases that don’t pull out with the
heat gun, I often remove them with a trim
iron rather than risk getting too close with a
heat gun. Reseal all seams after shrinking
with a heat gun.
At this point I trim the ends of the
finished heat-shrunk yellow wing panel
using a cardboard pattern, a new X-Acto
blade, and a light touch. I apply enough
pressure to cut only the film—not the balsa
under it. I also trim the TE, leaving roughly
1/8 inch wrapped around the upper side of
the wing.
As I mentioned, the Tiger 400’s tips will
be covered in white. If you are doing a onecolor
scheme, finish the tips first so that the
wing film will overlap them. I start with the
bottom of the tip and then cover the top.
Tack the film on the high point or spar
position of the top of the end rib, and then
stretch and seal that rib to the TE. Repeat
the process for the LE. Beginning at the
same spar location, stretch the film and seal
it to the outer edges of the tip. When
finished, carefully shrink the film and trim
off the excess.
Repeat those steps for the top of the tip,
and you have one tip done. Covering these
components takes time, but the reward is
worth it.
To cover the remaining curved portions
of covering near the tip and wing center,
make a cardboard pattern to fit the space.
02sig2.QXD 12/22/08 11:08 AM Page 40
This will be almost the same shape that was
filled with sheet 1/16 balsa. Add extra film to
the uncurved edges.
To make this pattern and most of the
others, use thick poster board and a sharp
blade on the hobby knife to ensure a smooth
cut. When finished, I cut eight pieces of the
opaque white.
A trim iron comes in handy for attaching
the white panels. Keeping the seam small, I
tack at the lowest point of the curve. Then I
pull and seal the film to the TE, slightly
overlapping the yellow, and finish the curve.
I seal the center seam as well as the top
edge, smooth any wrinkles, push out air
bubbles, and close the seam at the bottom.
Shrinking the panel with a gun or iron
follows.
A delicate touch is required if you are
using a heat gun. Protect the panel next to it
with a piece of cardboard or a damp cloth,
to avoid burns. Use cotton to work out any
air bubbles. Repeat this process for all
panels. When finished, you can apply Top
Flite MonoKote Trim Solvent with a small
swab to seal the edge between the differentcolor
films.
After completing those panels, you’ll
probably find that the wing’s LE will be a
snap to cover. Of course, you’ll do the
bottom side first so that the top film
overlaps it.
The covering is attached along the spar
line. Tack it at the center, and then stretch
and seal it to the tip, taking care to keep the
line straight. Tack the LE in the center of
the wing panel, and tack and stretch at 1-
inch intervals in both directions.
When finished, all edges are sealed, the
panel is shrunk, and the excess material is
trimmed off using a straightedge. Now
cover both bottom panels and both top
panels.
At this point, my Tiger 400’s wing is
completely covered with the yellow and
white film. All that remains is to attach the
red trim.
The easiest way to attach a strip or much
of the other trim to a model is to use a
method involving Windex. It can virtually
eliminate air bubbles between layers of
film.
On my ARF, I sprayed a light coat of
the glass cleaner on the plastic, aligned the
white film where I wanted it, and used a
credit card to squeegee out the excess
liquid. I cleaned up and worked out any
remaining Windex with a tissue.
Pushing the credit card rather than
dragging it works better, and its edge can
be used quite effectively to nudge pieces of
film into place. If you have any persistent
air bubbles, prick them with a sharp pin
and work out the air. Let one side dry
overnight before doing the other side, or
you may regret it.
If the film overlaps an edge such as the
LE or TE, tack it to that edge with a trim
iron. When the film is dry, you can use
extremely low heat on a covering iron to
set the adhesive in the trim film and then
seal the edges with trim solvent. If a piece
does not look right when dried, it can
usually be lifted, sprayed, and repositioned.
To finish my ARF’s wings, I used an
incredibly sharp X-Acto knife to cut 1/4
inch of red trim from film in strips and
curves. The cardboard patterns for the
curves were easy to make with help from a
Hobbico Circle Cutter. I applied all the red
trim using Windex, set the adhesive with an
iron on low heat, and then sealed it using
trim solvent.
One of the hardest things to do is cut out
small trim pieces, such as the 1/4-inch-wide
curves for the red trim, and get a smooth
cut. I use the following tips for success.
Use a new, sharp X-Acto blade. Make
sure the pattern is smooth so that the knife
blade will not hang up on it. Tape one side
of the pattern down and, while keeping
pressure on it, cut the untaped edge in one
smooth, continuous motion. Without
moving the pattern, apply tape to the other
side of the pattern, remove the original
tape, and cut the remaining side. When
designing these curved pieces, allow extra
film to overlap the adjoining piece.
I decided to deviate from the plan and
add 1/8-inch red Great Planes Kwik Stripe
Striping Tape on top of the white side
stripe and 1/16-inch white tape along the
back edge of the tail surfaces, to echo the
line I formed on the wings.
I had not planned on using the red side
stripe; however, once the Tiger 400 was
finished, I felt like it needed one more
stripe to complete the trim scheme.
Striping tape was a fast and easy way to
obtain it.
Anyone can learn to cover a model. The
results can be rewarding and give your
airplane that custom, non-ARF look that
will set it apart at the flying field. As I did,
you might also gain an appreciation of how
good the work is that comes out of the
ARF factories.
Good covering and happy flying! MA
Jon Putnam
[email protected]
That was only part of the covering job;
there’s still a fuselage and a tail section to
do. You can find that part of the story and
many more photos on MA’s Sport Aviator
Web site.
—MA Staff
Sources:
Tiger 400 review, Jon Putnam’s complete
covering how-to:
Sport Aviator
www.masportaviator.com
Radio Control Model Airplanes (book) by
John Carroll:
Kalmbach Books
(800) 533-6644
www.kalmbach.com
There Are No Secrets (book) by Harry
Higley, Tom’s Techniques (book) by Tom
Ingram and Harry Higley:
Harry B. Higley & Sons, Inc.
433 W. Arquilla Dr.
Glenwood IL 60425
www.harryhigley.com
Covering RC Airplanes: Volume I (book) by
Faye Stilley, Covering RC Airplanes:
Volume II (book) by Faye Stilley:
RCStore.com
(888) 235-2021
https://secure.rcstore.com