Give your model “life” with these simple techniques
By Dave Garwood
Photos by the author, except as noted
As seen in the April 2008 Model Aviation.
Sometimes only a painted finish can produce the results we want for a model airplane. The main reason to finish a Scale model with paint rather than iron-on covering is that with a larger number of paint colors available, more accurate color matching greatly enhances the scale appearance. Additional reasons are to achieve the matte finish that is desirable on military models and to produce a “feather edge” for camouflage colors—not too sharp and not too fuzzy.
I am definitely not a high-level craftsman or a super detailer. I make plenty of building and finishing mistakes, and I believe that “if you can’t see it in the air, you don’t need it.” So no rivet detail for me, but I have learned how to use an airbrush and other detailing techniques to make a military model look sharp in the air.
This article shows how I finished and detailed a Sukhoi Su-25 Frogfoot and placed in a Scale contest with it. If I can do it, you can do it too.
Let’s begin with the completed airframe after primer paint has been applied to the model. One paint-finishing secret is to use spray cans when possible. There’s no sense in dragging out the compressor and the airbrush to paint large areas when a “rattle can” works so well.
One trick when using a spray can is to heat it in warm water just before spraying. This reduces the paint’s viscosity and increases the propellant’s pressure, allowing the container’s nozzle to perform at its best.
Make several passes with slow, even strokes, fully depressing the nozzle, staying approximately 12-14 inches from the surface. Take your time and build up the color coats slowly and carefully, thus avoiding paint runs. Give plenty of time for the new paint to dry before handling, and especially before applying masking tape.
My first color application on the Su-25 Frogfoot was the light gray, applied with a Testors Model Master 3-ounce spray can. When that dried, I sprayed yellow, from the 3-ounce can, on the front of the fuselage and on the leading edges (LEs) of the upper side of the wings.
Oops! I forgot to mask the clear canopy, which the observant reader will notice is missing from the yellow spray session. Most of the clear canopy as modeled gets painted, with only small areas left clear.
I masked the clear areas with plastic tape, gave the area to be painted a light sanding with 400-grit sandpaper, sprayed primer, and then sprayed the yellow. I was glad I had purchased a spare can of yellow paint.
Now back to the paint bench to take care of yellow overspray with more light gray—this time applied with the airbrush, which gives me much finer control of the paint. The yellow paint came in a glossy version only, and I rubbed it lightly with steel wool to knock off the shine.
In the photos, you can see prints of the full-scale Su-25K “White 9013” tacked to the board behind the bench. I used these pictures, as well as three-view drawings, as a guide to the canopy markings, the yellow, and the camouflage green and brown paint.
It’s time for airbrush fun: painting the freehand camouflage areas. Slowly and carefully I started with the outline of each area in one camo color, working to get the prototypical size and shape of the brown and green sections and paying attention to the distinctive military-camo soft edges—not too sharp and not too fuzzy. Then I gradually filled in the centers with airbrush strokes.
It’s hard to put too little paint on with the airbrush since it’s so easy to add more color. My main technique is to add a bit more at a time and build up the paint application until I get the look I want.
There are three camo colors—brown and two greens—so after two more sessions of building up the camo blobs with the airbrush, I’m starting to feel like I might have captured the look of the prototype aircraft. Make sure to note the colors’ “layer” order so you overlap them correctly. Try to always spray the light colors first and the darker colors later.
Additional details in this finishing job are the “9013” numerals, which were cut from sticky-back vinyl at the local truck lettering shop, and national insignia decals. They are easy to draw but require attention to detail to lay out correctly on the airframe. The markings have left and right mirror-image layouts, which I discovered by studying the photographs.
I added panel lines using a Sharpie Ultra Fine Point marker, an assortment of flexible plastic rulers, and three-view drawings from the internet and the Squadron Su-25 Frogfoot in Action book. Panel lines add substantial detail with minimal time and effort, and adding detail is the game in Scale modeling.
You can clean up Sharpie panel-line goofs by carefully applying isopropyl alcohol, which dissolves the ink but not the paint. And yes, I had to clean up a few mistakes.
Since the model was to be judged, I added under-wing weapon racks and display landing gear. I was hoping to distinguish my model from the others in the paddock when the judges reviewed them.
Judging at the Southern California Power Scale Soaring (PSS) Festival begins with scoring the scale outline, colors, markings, and detailing. Points can be added for craftsmanship, and models that are built from scratch rather than from a kit get extra points. In addition, there is a point bonus for flying the model at the event.
At the May 2007 PSS Festival, I entered the Frogfoot in the “Jets” category. Other categories are “Propeller,” “Civilian,” and “Foam.”
“Dave, you picked a tough year to enter best jets category since the F-86 Sabre is this year’s club project plane and there are seven of them here,” remarked one Inland Slope Rebels club member when I was taking my model to the judging area.
I was not one of the five finalists after the static judging, but after a flight demonstration, I gained enough points to finish in fourth place. I was happy with the results of my effort on this project—especially since I’m not an advanced craftsman or a super detailer.
The reason for this article is to encourage you to try the airbrush to expand your model-finishing skills. I’m happy I listened to other modelers’ encouragement and learned to use this tool.
Airbrush Technique
I’m going to cover the steps involved with airbrush painting; in this case, I’m working with masked areas of the Su-25. Freehand painting involves the same steps, just with more practice at handling the airbrush.
Preparing to paint the dark-green marking on the fin, I masked the lower limit of the green area of the fin with thin quality plastic tape (not cellophane or paper tape). This material applies evenly, can be curved when needed, allows for a sharp line between two areas, and peels off cleanly and easily when the painting is done.
Extend the masked area with lower-cost paper masking tape, and tape paper or card stock over the remainder of the fin’s unpainted parts to avoid unwanted overspray.
It’s time to airbrush the fin. I mix the paint and then set up and test my airbrush. Variables that affect the paint’s application include:
• The ratio of thinner to paint
• How much air pressure is delivered to the airbrush
• The distance the airbrush is held from the work surface
• The speed the airbrush is moved over the work surface
• How far the air-release button is depressed
• How much paint is mixed into the airstream
This process may look more complicated than it is in practice.
Always clean your airbrush after use. A dirty airbrush, or bent needle, will keep your airbrush from operating properly.
Following is the setup I used for all my Frogfoot’s airbrushed areas.
1. Mix Testors Model Master paint with Model Master thinner at a 1:1 ratio.
2. Set the compressor regulator to 28 psi.
3. Keep the distance from the airbrush tip to the work surface between 2 and 5 inches to produce a sharper or fuzzier edge.
4. Move the tool at a moderate or medium speed over the work—estimated at 6-8 inches per second.
5. I press the air-release button fully down every time I push it. It’s all or nothing for me.
6. On my Paasche H-Set single-action airbrush, the amount of paint that is mixed into the airstream is determined by turning a collar at the front of the tool. I turn it three “swings,” or three 1/3 rotations.
On a double-action airbrush, the amount of paint that is mixed into the airstream is determined by how far back the air-release button is pulled. I’m not coordinated enough to run a double-action airbrush, and so far I haven’t found it necessary for the painting work I do. There’s always more to learn; I’ve purchased a double-action airbrush and will soon try it on a project.
These adjustments and timings may be different in your situation, but practice spraying on card stock before you shoot paint on your model. You can see one of my test cards on the bench in the background of the close-up shots of work with the airbrush. I use the card to test the spray pattern at initial setup, after every paint-cup refill, and when I start on a new area.
It may be helpful to get a demonstration of airbrush setup and technique if you have a buddy who is willing to show you. If no tutor is available, there are plenty of airbrush-technique books available at libraries, at bookstores, and from airbrush manufacturers.
When painting a solid area, such as the fin tip, I start with the brush off to the side, depress the air button fully, pass the airbrush over the work, run it past the far edge, and then release the button. This is to release a steady and even application of paint across the paint target area.
Even when painting the camo blobs, I depress the button fully at all times to apply the paint. If I want to spray less paint, I turn back the collar at the front to reduce the amount of paint that is mixed into the airstream.
Pay close attention to the manufacturer’s instructions for cleaning the airbrush, and follow them carefully. There are some extremely close tolerances within an airbrush, and a small amount of dried paint will cause problems.
Consider what you’ll use for a compressed air source. The airbrush manufacturers sell “canned air,” but that gets expensive quickly and the pressure varies as the can cools in use and as it becomes depleted. I’ve heard of using spare tires and cylinders of compressed nitrogen to run the airbrush, but that’s more trouble than it needs to be and risks running out of compressed air at the wrong time.
Most airbrush artists use a compressor, and two main types are available: small bench-top compressors made especially for airbrushing and larger, general-purpose compressors made for tools powered by compressed air. And one of the tools they can power is an airbrush (as well as larger paint spray guns).
The small and large compressors cost approximately the same, but they don’t make the same amount of noise. The bench-top compressors either run all the time or start on demand when the air-release button on the airbrush is depressed. These smaller units were designed to run quietly but are not silent.
My general-purpose compressor has a 12-gallon storage tank. Although it makes a fearsome racket while it’s filling the tank, it’s blissfully silent when I’m painting. I close the door and leave the shop when the tank is filling, and between fills I have 45-60 minutes of working time with no motor running.
Painting Hints and Tips
1. Practice with the airbrush and spray cans before shooting paint on a model. You may learn that you need less paint than expected. A light touch on the nozzle and patience lead to good application of scale paint. Keep the can or airbrush moving while spraying.
2. Vinyl tape works better than paper masking tape; it gives a consistently clean edge line and peels off cleanly and easily.
3. Be wary of aggressive adhesive on masking materials; they can pull up paint even after it has dried thoroughly. Test your masking materials. You can cut down the adhesive aggressiveness by carefully applying talcum powder. Be conservative; it’s easy to use too much powder and remove all the stickiness.
4. Consider making one or more practice panels to check the spray pattern from the cans, paint coverage, decal coverage, and the masking materials’ performance.
5. Newsprint is not the best choice for masking off large areas that don’t receive paint. The ink can rub off on our hands and on the model. Brown wrapping paper works well.
6. Take your time and work carefully. Most mistakes can be fixed with a brush or toothpick application of more paint, but that generally takes more time than doing it right the first time.
7. Don’t forget panel lines; they dress up the airplane and require little extra work. I use an Ultra Fine Point Sharpie marker, a flexible plastic ruler, and plastic templates. You can clean up mistakes with isopropyl alcohol.
8. Don’t be too hard on yourself for lack of perfection. Plenty of full-scale warplanes were painted and repainted in the field under adverse conditions. Little mistakes often seem huge on the bench but are unnoticeable in the air. If you make a mistake, respray the base coat and start again in that area.
Working carefully, modelers with moderate skills can improve their models’ appearance using these techniques. It’s worth the effort. Few will notice if a Zero panel-line layout is applied to a Spitfire, but everyone can tell the difference between an airplane with panel lines and one without.
Comments
Add new comment