Spraying Your RC Car with Lexan Paint?

Firstly, it's important to understand that there are two major differences between remote-controlled cars with a Lexan (transparent, flexible) body and those with ABS (hard, colored plastic) bodies. Each type requires a totally different approach to painting and also a different kind of paint.

Let's first look into painting Lexan Bodies, which you'll find on remote-controlled cars from brands like Tamiya, Traxxas, ARRMA, and many more.

Painting a Lexan Body

Preparation is key and that might be even more true when it comes to painting your model. Always ensure you have a spacious and clean environment. The last thing you want is dust in your paint. Many people choose to spray paint outdoors; if you do this, be mindful of trees and tall plants, especially in spring and summer, as they often release a yellowish pollen that can seriously spoil your paint job.

Step 1: Cleaning the Body

For a good result, it's critical that the body is clean before you start masking. For the best outcome, there are special Lexan cleaners you can use. However, traditional dish soap (without fragrances or additives!) still works just fine. It's very important to dry the body thoroughly with a lint-free cloth afterward to avoid leaving any residue that could mar the finish.

Step 2: Masking the Body

With Lexan bodies, you do the masking and painting on the inside of the shell, which is usually covered with a protective film that should remain in place until you're finished with the painting. This prevents any spray mist from ruining the outside of the body. Make sure that the film is intact and has no damage, and if necessary, repair it with some tape.

For masking windows, most manufacturers include a pre-cut or drawn sticker sheet for the window shapes. This allows you to easily mask them off. Take your time with this step, as removing and reapplying the masking can often degrade the final appearance. Also, be cautious about handling the body too much with your fingers, as oils can leave prints and lead to imperfections in the paint or even cause the paint to peel after spraying.

If it's your first time spraying a body, don't complicate the task with complex patterns. Often, it's better to start with simple lines or a solid color for the best results. Setting the bar too high from the get-go can often be detrimental to the outcome. Use specialty masking tapes, like those from Tamiya and Revell, which won't damage your paint and don't leave behind any adhesive, even if applied days before painting. Cheaper tapes from hardware stores might not perform as well.

When masking for multiple colors, remember that since you're spraying from the inside of the body, you should start with the darkest color (black, blue, green) and work your way to the lighter colors. So, you mask off the lighter colors first.

Step 3: Actually Spraying the Body

Once everything is properly masked with no air bubbles or lifted edges, it's time to start. As mentioned, always work from dark to light to prevent dark paint from showing through the lighter colors.

To spray effectively, ensure the can is at room temperature or slightly warmer. A common trick is to place the spray cans in lukewarm water (about 40-50 degrees Celsius) to slightly increase the pressure and make the spraying smoother. Shaking the can well is essential to evenly distribute the paint and avoid sputtering.

The environment for spraying should not only be clean but also dry; even if you're spraying indoors, the outside humidity can affect the finish. While Lexan paints are less sensitive to this, the best results are achieved on a dry day without any fog. The ideal temperature is between 15 and 25 degrees Celsius.

With Lexan paint, always start with very thin layers. The paint is often not 100% opaque, so it may take a few coats before you see the true color emerging. Resist the temptation to apply thick coats too quickly, as this can lead to runs and other unsightly effects. To check coverage, look at the body against the light to ensure the color is even. If not, apply more layers until you achieve an even tone. Some colors will never be completely opaque, so once the color is uniform, refrain from adding extra layers. Further instructions will guide you on dealing with this when painting Lexan bodies.

After spraying the darkest color, move on to the next darkest color until all colors are done. For bright and deep metallic colors, you might need to back the paint job, typically with black, white, or silver, to bring the colors to life. The effect varies depending on the color:

  • Black: Darkens the overall body and can give a deep effect on transparent metallic colors.
  • White: Lightens and brightens the color, often used for neon colors to make them pop.
  • Silver: Enhances the depth of the paint while keeping the color neutral, impacting clear colors based on the lighter color used.

Step 4: Cutting and Assembling

Now that your model is fully painted, it's time to cut out the body and assemble it. You'll need a pair of Lexan scissors, which are specially designed for this purpose and work much better than regular scissors. It's wise to roughly cut out the large sections first to make it easier to get into the corners later. Always maintain a cutting motion and avoid closing the scissors completely during a cut, as this can create unsightly "break" lines.

Once the body is cut out, use a sanding block and an empty jam jar to smooth out any frays. The sanding block can neatly finish straight lines and remove any frays, which can become tear risks during driving. The jam jar or another appropriately sized container makes it easier to sand round the wheel arch edges smoothly.

The final step is ensuring the body posts are correctly positioned, as you don't want the body to sit askew on your car. There are tricks to make this easier, such as shortening the body posts to about 1cm longer than needed. Then, apply pieces of tape inside the body where the posts are estimated to be. Apply some correction fluid or paint to the body posts, and when you position the body carefully on the car, you'll see clear marks on the tape where to drill the holes. Use a special Lexan drill for this, not a power drill, as it can catch on the thin material and tear the body.

Step 5: Almost Done!

Now that your body is painted, cut out, and assembled, you can remove the protective film from the outside. This film has protected the body from spray mist during painting. With the film off, it's time to apply the decals. Some bodies come with pre-cut decals for easy application; others may require you to cut them out. Applying the decals is straightforward but precise. You're free to decide which decals you want to apply to the body.

Common Mistakes Oops!

Of course, things can go wrong during painting, but many issues are easily explained and serve as learning opportunities for your next model. If it's just the paint that didn't work out, you might consider using a 'paint killer' to remove the old paint from your body, though results vary depending on the paint and body—so a clean finish isn't guaranteed.

Spraying the Paint Too Thickly: This common mistake is made by many eager modelers. Unfortunately, this can cause runs in the paint and prevent it from drying properly. Lexan paint dries best in thin layers because it needs to evaporate.

Mixing Different Brands of Lexan Paint: It's not recommended to mix paint brands, as they might react due to different compositions, leading to bubbling or peeling.

Improper Masking: Masking is a precision task. Even a small gap can let paint seep through, so take your time.

Insufficient Cleaning: Oils and residues can prevent paint from adhering properly, leading to fingerprints or smudges in the finish.

Not Removing Frays or Tears Before Driving: Failing to sand down the edges can lead to tears in the body upon impact, reducing its lifespan.

Incorrect Environmental Conditions: Paint is sensitive to humidity, temperature, and moisture. Ensure you paint under the right conditions for the best results.