MY FIRST COLUMN got many people
thinking about the state of our sport. We
are creatures of habit, and the most often
asked questions are related to building and
flying. The topic people ask the most about
is finishing.
Much of the work I’ve done has been
circulated, modified, and printed by others,
with and without my knowledge. Because
it is such a hot topic, I will present the
unabridged, updated version of the
finishing system created eight years ago. It
has consistently received high marks from
experienced judges.
With roughly 600 hours devoted solely
to finishing in the past eight years, when it
comes to finishing, for me there is “no
fear.”
The most important part of the finish is
the preparation for color. The most
important tool you will ever own is
sandpaper. If you want a first-class finish,
you will have to become good friends with
a variety of types and grits of the stuff.
There is definitely an art to sanding, and
the key is touch. Sandpaper is a tool; let the
tool do the work. It sounds simple.
Everyone knows what sandpaper is and
we’ve used it for many years, so why is it
such a big deal?
It took me 30 years to figure out how to
use this basic tool and another 10 years to
perfect my technique! I could have cut my
learning time down to a few days were it not for stubbornness
and trying to find some magic paint, spray equipment, or super
polish. Today I can say with relative confidence that there is no
such thing.
An outstanding finishing system is detailed
Excellent builders and finishers with their Ares designs: Bob Duncan (L) with his 1959
version and Jim Tichy with his 1962 version.
Joe Reinhard launches a beautiful Strathmoor Detroit Stunter for
Bob McDonald on its winning flight. They are superb builders and
finishers.
The model on paint stand (foreground) is ready for wing covering
with medium-weight silkspan. In the background are the Olympic
Mk VI, Diva, and Ante—all finished using the author’s system.
My current finishing method is
Certified, Randolph, or Brodak dope for
color, with automotive toners added to get
those colors that are not available off the
shelf. Filler is vital, and my preference is
talc added to clear dope. For the final
coats I use automotive clear coat. The
result has been 18 or 19 points under some
extremely critical judging.
The Process: Sand all bare wood smooth
with 320-grit wet/dry sandpaper used dry.
At this point you might be tempted to
remove the excess dust from the wood
with a tack cloth or even a vacuum. Do not
do that.
Brush on two coats of clear model
dope, unthinned. When dry it will be
rough to the touch. Do not sand.
Cover all wood with .02-ounce carbon
mat or silkspan. My preference is for the
carbon veil. Brush on two more coats of
unthinned clear dope and let dry at least 24
hours. This will give you a good base.
Now it is time for the first sanding.
Sand lightly and thoroughly with 240-grit
wet/dry paper used dry. The best technique
is to apply light pressure and move in a
circular motion. Be careful not to sand
through the clear.
When you are finished sanding you
will have a fairly smooth surface with
many low spots. The small, shiny areas
can identify low spots. The next step will
be to fill these.
Pour full-strength clear dope in a large
container with a good-sealing lid. Add as
much talc as will stay suspended in the
dope, and stir and shake thoroughly.
Allow the mixture to settle for roughly 10
minutes.
This next, extremely important step is
to mix in a small amount of black dope—
just enough to make a light gray. The best
talc I have ever used comes from TAP
Plastics (www.tapplastics.com). It has no
odor or oils.
Thin this mixture only enough to get it
to go through your spray gun. I use a big,
inexpensive pressure-feed spray gun for
this. This type of spray gun is readily
available at almost any hardware store.
Spray on a medium-heavy coat of this
filler. Let it dry 24-48 hours.
Here’s the cool part. You’re going to
sand off 80%-90% of this filler and you’ll
hardly break a sweat! This stuff powders
off like crazy! It took only three hours for
me to sand an entire Classic model,
leaving only enough material on the
airframe to fill the imperfections.
Since this mixture is gray, you will be
able to tell where the remaining low spots
and areas are that need more work. There
is no need to get out the spray gun again;
just spot these areas with a brush and sand.
Once everything is uniform, you will
have little spots of the gray filler all over.
When everything is completely filled and
sanded, clean the airframe thoroughly with
Windex or other glass cleaner and wipe
with a tack cloth to remove the dust.
The final step in preparation for color is
extraordinarily important and will help
prevent your base coat from coming off
when you remove the masking tape. Thin
clear dope 80%—that’s right, 80%—and
spray on a quick, wet coat. Do not skip this
last thin coat of clear or you could have a
mess when you remove the masking tape
during the trim.
Thin all colors 50%-60% and spray on
dry. Use just enough to cover; don’t worry
about shine, blushing, or even this coat
being a little rough. Once all colors are on,
spray on two coats of clear dope thinned
60%. Again, don’t worry about shine or
blush.
Lightly sand everything with 800-grit
wet paper. It is unnecessary to sand until
everything is completely dull.
The best solution for wet-sanding is
plain tap water, lukewarm, with roughly
three drops of dish detergent mixed into a
gallon. Be careful not to sand through the
clear coats.
Once everything is sanded, clean
everything with Windex or a similar glass
cleaner. Clean the entire airframe at least
two times. I usually do this four times.
Chemical degreasers don’t get the job done.
What you really want to do with this
cleaning is remove everything that is not
fixed permanently to the surface.
The reason for all the cleaning is that
almost all the dust particles that end up in
the final clear coat are on the airplane to
begin with; very little comes from the air.
Once you have cleaned and recleaned, go
over everything with a tack cloth several
times, being careful to apply only light
pressure.
Now you’re ready for the main event.
Lightly apply one coat of clear; my
preference is for automotive clear. It will
require good spray equipment, proper
ventilation, and breathing equipment.
Consult your local supplier regarding safety
precautions, spray equipment, and proper
mixture.
I use PPG Global Performance System
Clear D893 and D871 Medium thinner/
reducer. PPG is my preference, but there
are probably other clear coats that will
work, and they might be less expensive or
more readily available in your area.
The PPG system is a three-part paint,
clear, catalyst, and reducer/thinner. I use
50% reducer to get a water-thin mixture. I
also use a very good gravity-fed touch-up
gun to put on a light but even coat. The
PPG will flow out evenly and be dust free
in approximately 10 minutes. The model
can be handled in roughly two to four
hours, but let it dry for 24 hours anyway.
At this point your model will shine like
glass, and, depending on how much dust
you have in your spray area, you might be
finished! If there is dust, fear not; the
next two steps will produce a shiny,
smooth finish.
Wet-sand with 1,200-grit paper so
that everything is dull, with no shiny
spots. Spray on another coat of the clear
PPG. Let this final coat dry for 72 hours.
If you are happy with the glasslike
finish, quit here and go flying! If you
want that deep, ultrasmooth luster seen
on the front rows of appearance judging
at the Nats, you will have to wet-sand
again and rub out the finish. For the
ultimate finish, wet-sand with 1,200- or
1,500-grit wet/dry paper using the waterand-
soap solution, and rub out with a
fine grade of rubbing compound.
This whole process will add 9-10
ounces to a large airplane with a 750-
square-inch wing area. It added only 6
ounces to my Vulcan Classic model. The
overall weight of this finish is
reasonable, offering consistent results
from airplane to airplane.
Much of the rubbing and polishing is
done using yet another system I created
that uses common power tools. The next
column will feature details.
Until then, rely on the fact that
something is working to validate the fact
that it does work.
Edition: Model Aviation - 2007/01
Page Numbers: 138,140,142,144
Edition: Model Aviation - 2007/01
Page Numbers: 138,140,142,144
MY FIRST COLUMN got many people
thinking about the state of our sport. We
are creatures of habit, and the most often
asked questions are related to building and
flying. The topic people ask the most about
is finishing.
Much of the work I’ve done has been
circulated, modified, and printed by others,
with and without my knowledge. Because
it is such a hot topic, I will present the
unabridged, updated version of the
finishing system created eight years ago. It
has consistently received high marks from
experienced judges.
With roughly 600 hours devoted solely
to finishing in the past eight years, when it
comes to finishing, for me there is “no
fear.”
The most important part of the finish is
the preparation for color. The most
important tool you will ever own is
sandpaper. If you want a first-class finish,
you will have to become good friends with
a variety of types and grits of the stuff.
There is definitely an art to sanding, and
the key is touch. Sandpaper is a tool; let the
tool do the work. It sounds simple.
Everyone knows what sandpaper is and
we’ve used it for many years, so why is it
such a big deal?
It took me 30 years to figure out how to
use this basic tool and another 10 years to
perfect my technique! I could have cut my
learning time down to a few days were it not for stubbornness
and trying to find some magic paint, spray equipment, or super
polish. Today I can say with relative confidence that there is no
such thing.
An outstanding finishing system is detailed
Excellent builders and finishers with their Ares designs: Bob Duncan (L) with his 1959
version and Jim Tichy with his 1962 version.
Joe Reinhard launches a beautiful Strathmoor Detroit Stunter for
Bob McDonald on its winning flight. They are superb builders and
finishers.
The model on paint stand (foreground) is ready for wing covering
with medium-weight silkspan. In the background are the Olympic
Mk VI, Diva, and Ante—all finished using the author’s system.
My current finishing method is
Certified, Randolph, or Brodak dope for
color, with automotive toners added to get
those colors that are not available off the
shelf. Filler is vital, and my preference is
talc added to clear dope. For the final
coats I use automotive clear coat. The
result has been 18 or 19 points under some
extremely critical judging.
The Process: Sand all bare wood smooth
with 320-grit wet/dry sandpaper used dry.
At this point you might be tempted to
remove the excess dust from the wood
with a tack cloth or even a vacuum. Do not
do that.
Brush on two coats of clear model
dope, unthinned. When dry it will be
rough to the touch. Do not sand.
Cover all wood with .02-ounce carbon
mat or silkspan. My preference is for the
carbon veil. Brush on two more coats of
unthinned clear dope and let dry at least 24
hours. This will give you a good base.
Now it is time for the first sanding.
Sand lightly and thoroughly with 240-grit
wet/dry paper used dry. The best technique
is to apply light pressure and move in a
circular motion. Be careful not to sand
through the clear.
When you are finished sanding you
will have a fairly smooth surface with
many low spots. The small, shiny areas
can identify low spots. The next step will
be to fill these.
Pour full-strength clear dope in a large
container with a good-sealing lid. Add as
much talc as will stay suspended in the
dope, and stir and shake thoroughly.
Allow the mixture to settle for roughly 10
minutes.
This next, extremely important step is
to mix in a small amount of black dope—
just enough to make a light gray. The best
talc I have ever used comes from TAP
Plastics (www.tapplastics.com). It has no
odor or oils.
Thin this mixture only enough to get it
to go through your spray gun. I use a big,
inexpensive pressure-feed spray gun for
this. This type of spray gun is readily
available at almost any hardware store.
Spray on a medium-heavy coat of this
filler. Let it dry 24-48 hours.
Here’s the cool part. You’re going to
sand off 80%-90% of this filler and you’ll
hardly break a sweat! This stuff powders
off like crazy! It took only three hours for
me to sand an entire Classic model,
leaving only enough material on the
airframe to fill the imperfections.
Since this mixture is gray, you will be
able to tell where the remaining low spots
and areas are that need more work. There
is no need to get out the spray gun again;
just spot these areas with a brush and sand.
Once everything is uniform, you will
have little spots of the gray filler all over.
When everything is completely filled and
sanded, clean the airframe thoroughly with
Windex or other glass cleaner and wipe
with a tack cloth to remove the dust.
The final step in preparation for color is
extraordinarily important and will help
prevent your base coat from coming off
when you remove the masking tape. Thin
clear dope 80%—that’s right, 80%—and
spray on a quick, wet coat. Do not skip this
last thin coat of clear or you could have a
mess when you remove the masking tape
during the trim.
Thin all colors 50%-60% and spray on
dry. Use just enough to cover; don’t worry
about shine, blushing, or even this coat
being a little rough. Once all colors are on,
spray on two coats of clear dope thinned
60%. Again, don’t worry about shine or
blush.
Lightly sand everything with 800-grit
wet paper. It is unnecessary to sand until
everything is completely dull.
The best solution for wet-sanding is
plain tap water, lukewarm, with roughly
three drops of dish detergent mixed into a
gallon. Be careful not to sand through the
clear coats.
Once everything is sanded, clean
everything with Windex or a similar glass
cleaner. Clean the entire airframe at least
two times. I usually do this four times.
Chemical degreasers don’t get the job done.
What you really want to do with this
cleaning is remove everything that is not
fixed permanently to the surface.
The reason for all the cleaning is that
almost all the dust particles that end up in
the final clear coat are on the airplane to
begin with; very little comes from the air.
Once you have cleaned and recleaned, go
over everything with a tack cloth several
times, being careful to apply only light
pressure.
Now you’re ready for the main event.
Lightly apply one coat of clear; my
preference is for automotive clear. It will
require good spray equipment, proper
ventilation, and breathing equipment.
Consult your local supplier regarding safety
precautions, spray equipment, and proper
mixture.
I use PPG Global Performance System
Clear D893 and D871 Medium thinner/
reducer. PPG is my preference, but there
are probably other clear coats that will
work, and they might be less expensive or
more readily available in your area.
The PPG system is a three-part paint,
clear, catalyst, and reducer/thinner. I use
50% reducer to get a water-thin mixture. I
also use a very good gravity-fed touch-up
gun to put on a light but even coat. The
PPG will flow out evenly and be dust free
in approximately 10 minutes. The model
can be handled in roughly two to four
hours, but let it dry for 24 hours anyway.
At this point your model will shine like
glass, and, depending on how much dust
you have in your spray area, you might be
finished! If there is dust, fear not; the
next two steps will produce a shiny,
smooth finish.
Wet-sand with 1,200-grit paper so
that everything is dull, with no shiny
spots. Spray on another coat of the clear
PPG. Let this final coat dry for 72 hours.
If you are happy with the glasslike
finish, quit here and go flying! If you
want that deep, ultrasmooth luster seen
on the front rows of appearance judging
at the Nats, you will have to wet-sand
again and rub out the finish. For the
ultimate finish, wet-sand with 1,200- or
1,500-grit wet/dry paper using the waterand-
soap solution, and rub out with a
fine grade of rubbing compound.
This whole process will add 9-10
ounces to a large airplane with a 750-
square-inch wing area. It added only 6
ounces to my Vulcan Classic model. The
overall weight of this finish is
reasonable, offering consistent results
from airplane to airplane.
Much of the rubbing and polishing is
done using yet another system I created
that uses common power tools. The next
column will feature details.
Until then, rely on the fact that
something is working to validate the fact
that it does work.
Edition: Model Aviation - 2007/01
Page Numbers: 138,140,142,144
MY FIRST COLUMN got many people
thinking about the state of our sport. We
are creatures of habit, and the most often
asked questions are related to building and
flying. The topic people ask the most about
is finishing.
Much of the work I’ve done has been
circulated, modified, and printed by others,
with and without my knowledge. Because
it is such a hot topic, I will present the
unabridged, updated version of the
finishing system created eight years ago. It
has consistently received high marks from
experienced judges.
With roughly 600 hours devoted solely
to finishing in the past eight years, when it
comes to finishing, for me there is “no
fear.”
The most important part of the finish is
the preparation for color. The most
important tool you will ever own is
sandpaper. If you want a first-class finish,
you will have to become good friends with
a variety of types and grits of the stuff.
There is definitely an art to sanding, and
the key is touch. Sandpaper is a tool; let the
tool do the work. It sounds simple.
Everyone knows what sandpaper is and
we’ve used it for many years, so why is it
such a big deal?
It took me 30 years to figure out how to
use this basic tool and another 10 years to
perfect my technique! I could have cut my
learning time down to a few days were it not for stubbornness
and trying to find some magic paint, spray equipment, or super
polish. Today I can say with relative confidence that there is no
such thing.
An outstanding finishing system is detailed
Excellent builders and finishers with their Ares designs: Bob Duncan (L) with his 1959
version and Jim Tichy with his 1962 version.
Joe Reinhard launches a beautiful Strathmoor Detroit Stunter for
Bob McDonald on its winning flight. They are superb builders and
finishers.
The model on paint stand (foreground) is ready for wing covering
with medium-weight silkspan. In the background are the Olympic
Mk VI, Diva, and Ante—all finished using the author’s system.
My current finishing method is
Certified, Randolph, or Brodak dope for
color, with automotive toners added to get
those colors that are not available off the
shelf. Filler is vital, and my preference is
talc added to clear dope. For the final
coats I use automotive clear coat. The
result has been 18 or 19 points under some
extremely critical judging.
The Process: Sand all bare wood smooth
with 320-grit wet/dry sandpaper used dry.
At this point you might be tempted to
remove the excess dust from the wood
with a tack cloth or even a vacuum. Do not
do that.
Brush on two coats of clear model
dope, unthinned. When dry it will be
rough to the touch. Do not sand.
Cover all wood with .02-ounce carbon
mat or silkspan. My preference is for the
carbon veil. Brush on two more coats of
unthinned clear dope and let dry at least 24
hours. This will give you a good base.
Now it is time for the first sanding.
Sand lightly and thoroughly with 240-grit
wet/dry paper used dry. The best technique
is to apply light pressure and move in a
circular motion. Be careful not to sand
through the clear.
When you are finished sanding you
will have a fairly smooth surface with
many low spots. The small, shiny areas
can identify low spots. The next step will
be to fill these.
Pour full-strength clear dope in a large
container with a good-sealing lid. Add as
much talc as will stay suspended in the
dope, and stir and shake thoroughly.
Allow the mixture to settle for roughly 10
minutes.
This next, extremely important step is
to mix in a small amount of black dope—
just enough to make a light gray. The best
talc I have ever used comes from TAP
Plastics (www.tapplastics.com). It has no
odor or oils.
Thin this mixture only enough to get it
to go through your spray gun. I use a big,
inexpensive pressure-feed spray gun for
this. This type of spray gun is readily
available at almost any hardware store.
Spray on a medium-heavy coat of this
filler. Let it dry 24-48 hours.
Here’s the cool part. You’re going to
sand off 80%-90% of this filler and you’ll
hardly break a sweat! This stuff powders
off like crazy! It took only three hours for
me to sand an entire Classic model,
leaving only enough material on the
airframe to fill the imperfections.
Since this mixture is gray, you will be
able to tell where the remaining low spots
and areas are that need more work. There
is no need to get out the spray gun again;
just spot these areas with a brush and sand.
Once everything is uniform, you will
have little spots of the gray filler all over.
When everything is completely filled and
sanded, clean the airframe thoroughly with
Windex or other glass cleaner and wipe
with a tack cloth to remove the dust.
The final step in preparation for color is
extraordinarily important and will help
prevent your base coat from coming off
when you remove the masking tape. Thin
clear dope 80%—that’s right, 80%—and
spray on a quick, wet coat. Do not skip this
last thin coat of clear or you could have a
mess when you remove the masking tape
during the trim.
Thin all colors 50%-60% and spray on
dry. Use just enough to cover; don’t worry
about shine, blushing, or even this coat
being a little rough. Once all colors are on,
spray on two coats of clear dope thinned
60%. Again, don’t worry about shine or
blush.
Lightly sand everything with 800-grit
wet paper. It is unnecessary to sand until
everything is completely dull.
The best solution for wet-sanding is
plain tap water, lukewarm, with roughly
three drops of dish detergent mixed into a
gallon. Be careful not to sand through the
clear coats.
Once everything is sanded, clean
everything with Windex or a similar glass
cleaner. Clean the entire airframe at least
two times. I usually do this four times.
Chemical degreasers don’t get the job done.
What you really want to do with this
cleaning is remove everything that is not
fixed permanently to the surface.
The reason for all the cleaning is that
almost all the dust particles that end up in
the final clear coat are on the airplane to
begin with; very little comes from the air.
Once you have cleaned and recleaned, go
over everything with a tack cloth several
times, being careful to apply only light
pressure.
Now you’re ready for the main event.
Lightly apply one coat of clear; my
preference is for automotive clear. It will
require good spray equipment, proper
ventilation, and breathing equipment.
Consult your local supplier regarding safety
precautions, spray equipment, and proper
mixture.
I use PPG Global Performance System
Clear D893 and D871 Medium thinner/
reducer. PPG is my preference, but there
are probably other clear coats that will
work, and they might be less expensive or
more readily available in your area.
The PPG system is a three-part paint,
clear, catalyst, and reducer/thinner. I use
50% reducer to get a water-thin mixture. I
also use a very good gravity-fed touch-up
gun to put on a light but even coat. The
PPG will flow out evenly and be dust free
in approximately 10 minutes. The model
can be handled in roughly two to four
hours, but let it dry for 24 hours anyway.
At this point your model will shine like
glass, and, depending on how much dust
you have in your spray area, you might be
finished! If there is dust, fear not; the
next two steps will produce a shiny,
smooth finish.
Wet-sand with 1,200-grit paper so
that everything is dull, with no shiny
spots. Spray on another coat of the clear
PPG. Let this final coat dry for 72 hours.
If you are happy with the glasslike
finish, quit here and go flying! If you
want that deep, ultrasmooth luster seen
on the front rows of appearance judging
at the Nats, you will have to wet-sand
again and rub out the finish. For the
ultimate finish, wet-sand with 1,200- or
1,500-grit wet/dry paper using the waterand-
soap solution, and rub out with a
fine grade of rubbing compound.
This whole process will add 9-10
ounces to a large airplane with a 750-
square-inch wing area. It added only 6
ounces to my Vulcan Classic model. The
overall weight of this finish is
reasonable, offering consistent results
from airplane to airplane.
Much of the rubbing and polishing is
done using yet another system I created
that uses common power tools. The next
column will feature details.
Until then, rely on the fact that
something is working to validate the fact
that it does work.
Edition: Model Aviation - 2007/01
Page Numbers: 138,140,142,144
MY FIRST COLUMN got many people
thinking about the state of our sport. We
are creatures of habit, and the most often
asked questions are related to building and
flying. The topic people ask the most about
is finishing.
Much of the work I’ve done has been
circulated, modified, and printed by others,
with and without my knowledge. Because
it is such a hot topic, I will present the
unabridged, updated version of the
finishing system created eight years ago. It
has consistently received high marks from
experienced judges.
With roughly 600 hours devoted solely
to finishing in the past eight years, when it
comes to finishing, for me there is “no
fear.”
The most important part of the finish is
the preparation for color. The most
important tool you will ever own is
sandpaper. If you want a first-class finish,
you will have to become good friends with
a variety of types and grits of the stuff.
There is definitely an art to sanding, and
the key is touch. Sandpaper is a tool; let the
tool do the work. It sounds simple.
Everyone knows what sandpaper is and
we’ve used it for many years, so why is it
such a big deal?
It took me 30 years to figure out how to
use this basic tool and another 10 years to
perfect my technique! I could have cut my
learning time down to a few days were it not for stubbornness
and trying to find some magic paint, spray equipment, or super
polish. Today I can say with relative confidence that there is no
such thing.
An outstanding finishing system is detailed
Excellent builders and finishers with their Ares designs: Bob Duncan (L) with his 1959
version and Jim Tichy with his 1962 version.
Joe Reinhard launches a beautiful Strathmoor Detroit Stunter for
Bob McDonald on its winning flight. They are superb builders and
finishers.
The model on paint stand (foreground) is ready for wing covering
with medium-weight silkspan. In the background are the Olympic
Mk VI, Diva, and Ante—all finished using the author’s system.
My current finishing method is
Certified, Randolph, or Brodak dope for
color, with automotive toners added to get
those colors that are not available off the
shelf. Filler is vital, and my preference is
talc added to clear dope. For the final
coats I use automotive clear coat. The
result has been 18 or 19 points under some
extremely critical judging.
The Process: Sand all bare wood smooth
with 320-grit wet/dry sandpaper used dry.
At this point you might be tempted to
remove the excess dust from the wood
with a tack cloth or even a vacuum. Do not
do that.
Brush on two coats of clear model
dope, unthinned. When dry it will be
rough to the touch. Do not sand.
Cover all wood with .02-ounce carbon
mat or silkspan. My preference is for the
carbon veil. Brush on two more coats of
unthinned clear dope and let dry at least 24
hours. This will give you a good base.
Now it is time for the first sanding.
Sand lightly and thoroughly with 240-grit
wet/dry paper used dry. The best technique
is to apply light pressure and move in a
circular motion. Be careful not to sand
through the clear.
When you are finished sanding you
will have a fairly smooth surface with
many low spots. The small, shiny areas
can identify low spots. The next step will
be to fill these.
Pour full-strength clear dope in a large
container with a good-sealing lid. Add as
much talc as will stay suspended in the
dope, and stir and shake thoroughly.
Allow the mixture to settle for roughly 10
minutes.
This next, extremely important step is
to mix in a small amount of black dope—
just enough to make a light gray. The best
talc I have ever used comes from TAP
Plastics (www.tapplastics.com). It has no
odor or oils.
Thin this mixture only enough to get it
to go through your spray gun. I use a big,
inexpensive pressure-feed spray gun for
this. This type of spray gun is readily
available at almost any hardware store.
Spray on a medium-heavy coat of this
filler. Let it dry 24-48 hours.
Here’s the cool part. You’re going to
sand off 80%-90% of this filler and you’ll
hardly break a sweat! This stuff powders
off like crazy! It took only three hours for
me to sand an entire Classic model,
leaving only enough material on the
airframe to fill the imperfections.
Since this mixture is gray, you will be
able to tell where the remaining low spots
and areas are that need more work. There
is no need to get out the spray gun again;
just spot these areas with a brush and sand.
Once everything is uniform, you will
have little spots of the gray filler all over.
When everything is completely filled and
sanded, clean the airframe thoroughly with
Windex or other glass cleaner and wipe
with a tack cloth to remove the dust.
The final step in preparation for color is
extraordinarily important and will help
prevent your base coat from coming off
when you remove the masking tape. Thin
clear dope 80%—that’s right, 80%—and
spray on a quick, wet coat. Do not skip this
last thin coat of clear or you could have a
mess when you remove the masking tape
during the trim.
Thin all colors 50%-60% and spray on
dry. Use just enough to cover; don’t worry
about shine, blushing, or even this coat
being a little rough. Once all colors are on,
spray on two coats of clear dope thinned
60%. Again, don’t worry about shine or
blush.
Lightly sand everything with 800-grit
wet paper. It is unnecessary to sand until
everything is completely dull.
The best solution for wet-sanding is
plain tap water, lukewarm, with roughly
three drops of dish detergent mixed into a
gallon. Be careful not to sand through the
clear coats.
Once everything is sanded, clean
everything with Windex or a similar glass
cleaner. Clean the entire airframe at least
two times. I usually do this four times.
Chemical degreasers don’t get the job done.
What you really want to do with this
cleaning is remove everything that is not
fixed permanently to the surface.
The reason for all the cleaning is that
almost all the dust particles that end up in
the final clear coat are on the airplane to
begin with; very little comes from the air.
Once you have cleaned and recleaned, go
over everything with a tack cloth several
times, being careful to apply only light
pressure.
Now you’re ready for the main event.
Lightly apply one coat of clear; my
preference is for automotive clear. It will
require good spray equipment, proper
ventilation, and breathing equipment.
Consult your local supplier regarding safety
precautions, spray equipment, and proper
mixture.
I use PPG Global Performance System
Clear D893 and D871 Medium thinner/
reducer. PPG is my preference, but there
are probably other clear coats that will
work, and they might be less expensive or
more readily available in your area.
The PPG system is a three-part paint,
clear, catalyst, and reducer/thinner. I use
50% reducer to get a water-thin mixture. I
also use a very good gravity-fed touch-up
gun to put on a light but even coat. The
PPG will flow out evenly and be dust free
in approximately 10 minutes. The model
can be handled in roughly two to four
hours, but let it dry for 24 hours anyway.
At this point your model will shine like
glass, and, depending on how much dust
you have in your spray area, you might be
finished! If there is dust, fear not; the
next two steps will produce a shiny,
smooth finish.
Wet-sand with 1,200-grit paper so
that everything is dull, with no shiny
spots. Spray on another coat of the clear
PPG. Let this final coat dry for 72 hours.
If you are happy with the glasslike
finish, quit here and go flying! If you
want that deep, ultrasmooth luster seen
on the front rows of appearance judging
at the Nats, you will have to wet-sand
again and rub out the finish. For the
ultimate finish, wet-sand with 1,200- or
1,500-grit wet/dry paper using the waterand-
soap solution, and rub out with a
fine grade of rubbing compound.
This whole process will add 9-10
ounces to a large airplane with a 750-
square-inch wing area. It added only 6
ounces to my Vulcan Classic model. The
overall weight of this finish is
reasonable, offering consistent results
from airplane to airplane.
Much of the rubbing and polishing is
done using yet another system I created
that uses common power tools. The next
column will feature details.
Until then, rely on the fact that
something is working to validate the fact
that it does work.