Ah yes, the
paint job. This is the part of the plane that everyone sees first. You can
have a masterpiece of construction, but put a shoddy paint job on it and
your fellow aviators will judge your plane as a "homebuilt
Nevertheless, I have always
wanted to learn how to paint myself. I would also like to be able to make
my own repairs and changes without having to be dependent upon a paint shop.
paint job is where you can save a huge chunk of $ if you're willing to do
it yourself. For all these reasons I have committed to tackling the task myself.
|Making a decision on
a paint scheme was a struggle. All of my other decisions on the
panel layout, were fairly easy and made well ahead. Even though
I contemplated paint schemes since the very beginning, I couldn't
seem to lock in on one — not my typical pattern. Finally I narrowed it down to two basic options that I will
call "Extra 300 knockoff" and "Modified traditional
OPTION #1: Extra 300 knockoff
Here is my adaptation of the
standard Extra 300 scheme...
Modified traditional RV-4 scheme
My other choice is an adaptation of what
has evolved as the traditional RV-4 paint scheme, but modified with a
solid color vertical and horizontal stabilizers. The RV-8 tail is taller, with a different shape than an
RV-4 and I think it looks a bit awkward. Therefore I wanted to not do
anything to make it look taller. Vertical stripes make things look taller,
horizontal stripes would make it look shorter proportionately, solid would
be neutral in effect.
an RV-4 in the traditional scheme. There are many RV-4s (and -6s) out
there with derivations of this basic scheme. I don't know who started it
because none of the Van's demo planes are painted this way. Sorry, I don't
know who owns this particular aircraft.
|This is an RV-6 with a similar scheme but with a solid tail, which I like
better, especially with the RV-8's taller, more visually awkward tail. The
excellent work here was done by owner Tom Prokop of Chino, CA
Ok, after much thought and advice from other builder's I trust, I decided
on Option #2. Time to start the painting process!
|To begin the learning process I researched paint materials and
techniques thoroughly. I chose PPG Concept (aka DCC), an acrylic
urethane, as the paint. I shot the interior with Concept due to it's
durability, but also to learn more about how to work with the materials
before I got to the exterior. I was pleased with the way the interior turned out and therefore optimistic
(foolish?) about the exterior. Without a professional filtered-air paint
booth I knew there was no way I could keep the surface free from dirt,
dust, and bugs, but I was prepared to wet-sand and buff all surfaces.
Concept supposedly lends itself well to this and yields a mirror smooth
surface as a reward for the effort, however I later learned that I wanted to
avoid sanding/buffing if possible, not only is it more work, but you will
never recapture that virgin wet look once you sand/buff.
Of course anyone who's done any
painting knows that the actual painting process is a relatively small part
of the whole thing. Good surface prep work is essential to a good paint
job, and let me tell you, surface prep is a lot of work. The fiberglass
parts are of course more work than the aluminum, but then that's another
Below is the family of PPG
products I used...
(clic on a pic for larger image)
is the primer that I used for all the fiberglass parts. K38 is
relatively new and is intended to replace K36, which is fairly
well known. It is a high-build acrylic urethane primer and can be shot
directly over properly prepared aluminum or fiberglass. It is mixed 4-1
with K201 catalyst/hardener. It works very well, I highly
recommend it. It shoots very easily, dries reasonably quickly between
coats, and sands easily. One thing though, I would dedicate an older gun
to it - because of it's high-solids content is really can clog things up.
It's so easy to shoot that you don't need your best gun for it. I ended up
dedicating my $39.99 HVLP gun that I got from Harbor Freight Tools. to this
surfaces will be given "tooth" with Scotchbrite pads, cleaned,
and then primed with DX1791 self-etching wash primer. I have already shot
some test samples of of this and if I had it to build the airframe over
again I would have used it to prime the inside of the airplane. I primed the
airframe with Sherwin
Williams P60-G2 which is what Van's recommends and also uses on the Quickbuild kits. The DX1791 leaves a golden translucent finish that looks
nicer than the SW and also has a nicer semi-gloss finish to it.
actual paint is mixed 4-2-1 with paint, reducer, and hardener. There are
four different reducers to choose from depending on the temperature of
your painting environment and how fast you want it to set up... for large
surfaces you intentionally want a slow reducer so entire surface flows out
Paint color codes
|Many folks have asked for my
paint color codes, so I've listed them below. I get many comments in
particular on the red. It is quite a bit more
intense than reds typically used. In the process of selecting my colors by
testing small samples, and not liking several of them, I learned that
virtually all reds are really blends of red color base with various amounts
of black, blue, and yellow added to product different tints. None of the
samples I tried were really what I was looking for. Finally, one of the guys
in the paint shop suggested just shooting the red color base. I wasn't aware
this was possible, but he explained that the color base is the regular paint
formula that's used as a starting point for blending all colors in that hue.
I tested it and it was exactly what I was looking for.
These are PPG fleet colors and should be
available at any auto body supply store that carries PPG products, and
Concept DCC in particular:
||DMC 917 2k Mixing Base Color
I also get asked about paint
quantity. Overall I used nearly three gallons of paint for the exterior:
just about 2 gallons of white, 2 quarts of red, and about a cup and a half
of the gray. I'm sure you could get by with less paint, but once into the
painting process I realized that I needed 3 coats in most places for the
type of finish I was after and that drove the quantity up a bit.
you're going to paint you need a place to do it. Our house has a 3rd
garage space designed for a motorhome — higher ceiling and almost two
cars deep. This has been my "aircraft construction facility"
since the beginning, and I've occasionally used one of the other bays as
well. While not ideal as a paint booth, I've managed to make it work so
far. I took apart one of my Van's crates and put the wood back together in
the form of this spacer for the bottom of the garage door. I then cut
holes and mounted those box fans that every discount store has for $16.99.
Air comes in from a window about half way back in the space. It would be
ideal to have the door at the other end thus creating a complete
cross-flow, but hey, you gotta work with what you have.
hung heavy visqueen to seal off the construction bay (aka paint booth)
from the rest of the garage, and to form a bit of a tunnel through which
the fans would keep the air moving. It works ok under the circumstances. I
started off with just two fans and this moved enough air for smaller
parts. But as I've gotten into the larger parts and am spraying more paint
I find I need to move more air if I don't want a thin layer of paint all
over everything else in the garage. Recently I bought two more fans. The
first has been mounted, and it helps, but I will need to finish by adding
the fourth. This should move enough air to do the wings and fuselage...
is the first gun I bought. It's a gravity feed HVLP conversion gun from
Harbor Freight Tools, their part number 3808. I bought it on sale for
$39.99. This is an incredible value and an amazing gun for the price. You
could easily shoot your entire project with this gun, but it seemed
especially appropriate to dedicate as a primer gun. In the later stages of
my fiberglass work I was shooting lots of K38 which does tend to clog up
things a bit. In the early stages of the project I shot wash primer with
it, but later dedicated this gun to K38 and then shot all wash primer and
paint with the new DeVilbiss gun below.
|(pic of DeVilbiss
gun here with bladder system)
I bought this DeVilbiss GTi-600 primarily for the bladder system. I didn't
know how I was going to paint parts of the interior or the bottom of the
fuselage without it. This was a wise purchase... this gun is a gem. It
shoots well, is easy to adjust, is easy to clean, and has the bladder
system for inverted painting whenever you need it.
|(pic of HobbyAir
respirator system here)
painting starts with priming. The first exterior parts to get primed were
the cowling, spinner, and empennage fairing. They will get multiple coats
of K38 with lots of sanding in between. Wow,
check out these pinholes — the first coat of primer exposed pinholes everywhere!
You can't see these (at least I couldn't) before shooting the first coat
of primer. This may be due to the fact that my cowling has no gelcoat, but
it sure looked smooth to the naked eye. Obviously it's not! This means
some filler, more sanding, more coats of K38, and more sanding again. Fun!
October 8th, 2000, the exterior painting process began. Here I am, having
already scuffed, cleaned, and primed my ailerons and baggage door,
nervously about to begin shooting white Concept on a real piece of
the plane that people will actually be looking at. Whew, they ended up
turning out great, or at least good enough for me. They did take more
paint than I expected. I intended to shoot a "tack coat", then
two medium coats. This was based on what I could glean from other's
experience on the RV List, what is indicated on the Concept product sheet,
and my experience shooting the interior. I shot the tack coat, then a coat
that was probably lighter than it should have been because I was afraid
I'd run it. Then I put on a medium wet coat and took a look... still a bit
thin. So I waited 20 minutes, which is slightly longer than called for on
the data sheet, and shot another very wet coat — I figured these parts
were easy to sand any runs off, so I put a lot of paint on, trying
to sneak up on that fine line between orange peel and runs in search of
that elusive glossy flooded coat. You can see I'm wearing a nylon paint
suit and a Hobby Air fresh air respirator. I learned the hard way to get
something decent to wear. I started painting the interior with one of
those cheap fiber suits I got at the autobody supply place. The first use was
fine, but then it started wearing and shedding fibers all over. By the
third or fourth use it was really making a mess. This suit is called a
Shoot Suit and cost about $45. It is nylon, can't shed, and is machine
washable. If you are shooting anything with "urethane" in it you
want some sort of a fresh air respirator. These paints contain isocyanates
which are very nasty. The normal passive respirators which do a fine job
on organic solvents will not stop isocyanates. Be careful!
what a feeling, the first parts actually turned out pretty good! There is still just
a bit of orange peel, but no runs and pretty good gloss. The right hand
pic shows how the rivets look after three coats. Some have "bridged" while the others on the row by the hinge still have a
gap between the head and the dimple. With just two coats plus a tack coat
they were all like this. Going to the third coat got about half of them
filled in. The paint is fairly thick now so I didn't want to risk a fourth
spending a fair amount of time priming and eliminating the dreaded
pinholes in the elevator and rudder tips it was time to shoot them. These
parts looked pretty good after two coats, so in spite of putting three
coats on all parts I had shot with white previously, I stopped at two
coats. This was a mistake - none of the rivets filled in and it just
generally didn't look as thick and rich as it does with three coats.
Horizontal surfaces are much easier to get a nice finish on. With an HVLP
gun it is almost impossible to eliminate all the orange peel on a vertical
surface, or so the experts say. This picture shows the way the rudder horn
tip has been finished. The elevators have been done in the same manner
canopy skirt was finished next. The porous epoxy prepreg took one coat of
UV Smooth Prime which I applied with a small foam roller, then two
applications of PPG K38 high-fill primer. Each application of K38 was 2-4
coats, sanded almost all the way off in between applications. After the
last application sand just through the surface with 320 or 400 grit, then
you're ready to paint.
far I've learned that horizontal surfaces attract quite a bit more dirt and
debris in my makeshift paint booth than do vertical ones. On the other hand
it's easier to let the paint flow out and eliminate orange peel and runs
with a horizontal surface. I had planned on painting my wings vertically on
the storage stand that I built, but changed my mind at the last minute and
jigged them horizontally. I figured they were too prominent to end up with
an orange peeled surface. Runs would not be becoming either. The small dirt
and fiber specs could be sanded and buffed later if it bothered my that
much. As I figured out earlier, I used three coats of paint to fill in as many rivet heads
as possible, and also to give me enough material there to sand out any
imperfections later. At this point I have decided that I won't even worry
about the flaws now. Once the parts are on the airplane they can be sanded
more easily, and I can do it as time allows.
None of my parts so far look
what I would consider terrible in spite of the flaws. I
had some sags in the leading edge which I could get to flatten out by
orienting the wing properly. About a half hour after shooting the left wing
I oriented it vertically to flatten the sags and keep more dirt from landing
is how I jigged the end of the wing to rest in the chain cradle. The chain
was attached to the garage door tracks by drilling holes in the edge. An
added benefit of suspending at least one end is that you can move your hoses
around without catching on tables or stands.
never thought I'd see the day when this cowl would actually look like
something. With all the cutting, fiberglassing, sanding, filling, and more
sanding, I'm kind of stunned that it's done and actually looks ok.
Note the trick support system: no support in the back at all which enabled
me to move my air and respirator hoses back and forth underneath the plane without them catching on
anything. I have a hydraulic wing jack supporting the carburetor in the
front which let's me adjust the fuselage at any angle I want by simply
jacking it up or down... worked great!
fuselage after. The fuselage was tough to shoot. Why? Large areas are tough
to get an even coat on, light is always a challenge, and the combination of
horizontal and vertical surfaces is difficult to balance between orange peel
and runs. Then there's laying on your back to paint the bottom. I used a fluorescent
trouble light to see what I was doing and just laid on my back and sprayed
away. Actually the bottom is easy to shoot... it gets very few dirt
particles in it, and you can load the paint on for a nicely flooded coat and
it won't run because it's horizontal. Using a slow reducer is the only way
to get all the surfaces on a large object such as this to blend together,
but then of course you are more prone to runs, which I got a few of. This
reinforces my decision to use Concept in a non-metallic color... they're
relatively easy to sand and buff out!
Now it's on to the fuselage trim
colors — new territory for me.
much better with the gray, don't you think?
Of course there is lots I've learned about
painting that isn't detailed on this site, but let me just attempt to
summarize what I learned on several common issues...
Drying - I found the times to be fairly close
to what the data sheets say. Now "drying" is a relative term. A urethane
paint both dries in the sense that the thinners evaporate, and cures in
that a chemical reaction takes place which hardens the paint. I make
second coats in temps cooler than 70 after 15-20 minutes which I found to
be just about right. Too soon and the risk of a sag goes up, too late and
it won't chemically bond.
Orange peel - You will find that the
controlling the orientation of your surfaces will help. Anything
horizontal can be made to flow nicely without orange peel, but you will
pick up more dust and dirt. Vertical surfaces won't pick up much dirt, but
eliminating the orange peel without inducing runs in very very difficult.
Even in the best of conditions I'd say that total elimination of orange
peel while shooting a vertical surface is just about impossible.
Temperature - I shot much of my pieces in
40 degree temps and it really worked fine. It did take a bit longer to set
up, and I used faster reducer, but it was surprisingly temperature
Taping & trim - I waited several days just
so I wouldn't marr the paint. At that point you will not get a chemical
bond so after I taped things off I used Scotchbrite to scuff the
underlying paint... worked great, excellent adhesion
Hope that helps a bit
Go to the Picture
Gallery for pics of the finished product.