Painting an RC car body is one of the most satisfying parts of the hobby. A well-done custom paint job makes your car instantly recognizable at the track and shows that you put care into your build. The process is different from painting regular models because RC bodies are made from clear polycarbonate (Lexan), and you paint from the inside rather than the outside. This means the paint is protected by the body itself, so it does not chip or scratch from crashes and rubbing.
Como to Paint Custom RC Car Bodies
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The technique takes some practice, but the basics are straightforward once you understand how inside-out painting works.
What You Need
Polycarbonate-specific paint is essential.
Regular spray paint, enamel, or lacquer will not adhere to Lexan properly and will peel off. Tamiya PS series and Pactra RC paint are the most popular options. Both are formulated specifically for polycarbonate and flex with the body rather than cracking on impact.
You will also need masking tape (Tamiya curved masking tape works great for complex shapes), an X-Acto knife or fine scissors for cutting mask edges, liquid mask for areas with irregular borders, rubbing alcohol or window cleaner for degreasing, and paper towels.
If you want to use an airbrush for more detailed work, any airbrush setup that handles lacquer-based paints will work.
Thin your Tamiya PS paint about 60/40 paint to lacquer thinner for airbrush use. Spray cans are simpler and produce good results for most designs.
Step 1: Clean the Body
New polycarbonate bodies have a release agent on the surface from the manufacturing process. This oily film prevents paint from sticking properly. Wash the body inside and out with warm water and dish soap, scrubbing gently with a soft cloth.
Rinse thoroughly and let it dry completely.
After washing, wipe the inside surface with rubbing alcohol to remove any remaining residue. Do not touch the inside surface with your bare hands after cleaning, as the oils from your skin will create spots where paint does not adhere well. Handle the body by the edges or wear nitrile gloves.
Step 2: Plan Your Design
Because you paint from the inside, you need to apply colors in reverse order from lightest to darkest. The first color you spray will be the outermost layer visible from the outside. This is the opposite of conventional painting where you build up from dark to light.
Sketch your design on paper before you start masking. Note which colors go down first and where each mask needs to be placed.
For a simple two-tone design, you spray the lighter color first, mask over the areas you want to stay that color, then spray the darker color. For complex multi-color schemes, you repeat this process for each color layer.
The final layer is always the backing color, which is typically white or black. White backing makes all your colors appear brighter and more vivid. Black backing deepens the colors and works well with metallic or dark schemes.
Step 3: Masking
Apply your masking tape to the inside of the body along the lines where colors will change.
Press the tape down firmly along the edges to prevent paint from bleeding underneath. For curved lines, use narrow Tamiya curved masking tape that conforms to the body's contours without wrinkling.
For complex shapes or areas where tape is difficult to apply, liquid mask is useful. Paint it on with a brush, let it dry to a rubbery film, and it peels off cleanly after painting. It works well for window masks and irregular borders.
Cut your mask lines with a sharp blade, but be careful not to cut through the polycarbonate.
Score the tape only, not the body. A light touch with a fresh blade is all you need.
Cover any areas you do not want painted with newspaper or extra masking tape. Overspray is easy to avoid if you take the time to mask thoroughly.
Step 4: Painting
Shake your spray can vigorously for at least two minutes. This is not an exaggeration. Polycarbonate paint has pigments that settle quickly, and inadequate shaking results in uneven color and poor coverage.
Hold the can about 6 to 8 inches from the surface and spray in light, even passes. Multiple thin coats are always better than one heavy coat. Heavy coats run, pool, and take forever to dry. Thin coats build up color gradually and produce a smooth, even finish.
Wait 10 to 15 minutes between coats for the paint to flash off. Depending on the color, you will need three to five light coats for full coverage.
Lighter colors like yellow and white need more coats than darker colors like blue or black.
Metallic and fluorescent colors require a bit more care. They look best over a base of silver or white, so spray that base color first, let it dry, then apply the metallic or fluorescent color on top.
Step 5: Backing Coat
After all your design colors are applied and dry, remove all masking and apply a backing coat over the entire inside of the body.
White backing is the standard choice and makes colors pop. Use Tamiya PS-1 White or an equivalent backing white from your paint brand.
Apply three to four light coats of backing, making sure every area is fully covered with no thin spots. The backing coat serves two purposes: it makes colors visible and opaque from the outside, and it adds a layer of protection that helps the paint survive impacts.
Some painters use a dedicated backing paint that is thicker and more opaque than regular color coats.
Tamiya PS-55 Flat Clear followed by PS-1 White is a popular combination that provides an extra durable finish.
Step 6: Trimming and Finishing
Once the paint is fully dry (give it at least 24 hours), trim the body along the cut lines using curved Lexan scissors. Cut slightly outside the line and clean up with a body reamer or sandpaper on the edges.
Drill the body post holes using a body reamer or a step drill bit.
Go slowly to avoid cracking the polycarbonate. Mark your holes carefully by test-fitting the body on the chassis first.
Peel the protective film off the outside of the body to reveal your paint job. This is the moment of truth and the most satisfying part of the process. If everything went well, you have a clean, professional-looking custom body ready to hit the track.
Common Mistakes and How to Avoid Them
Paint bleeding under the mask is the most common issue. It happens when tape edges are not pressed down firmly or when you spray too heavy near mask lines. Always burnish tape edges with your fingernail or a plastic burnishing tool, and keep your spray passes light near masked areas.
Fisheyeing, which looks like small craters in the paint, happens when the surface is contaminated with oil or silicone. Thorough cleaning and degreasing before painting prevents this. If it happens, you need to strip the paint from that area with a polycarbonate-safe paint remover and start over after re-cleaning.
Patience is the biggest factor in getting good results. Rushing between coats, spraying too heavy, or peeling masks before paint is dry causes most of the problems beginners encounter. Give each step the time it needs and your results will improve dramatically.