
After sanding the car paint with sandpaper, the glossy surface layer is removed, which can make the paint appear white and lose its luster. Generally, after sanding and repainting the car paint, a layer of clear coat, also known as varnish, needs to be applied to enhance the brightness of the paint surface. Additionally, polishing and waxing the car body can also restore the paint's shine. The following are methods for maintaining car paint: 1. Remove dust: Before, during, and after using the vehicle, promptly remove dust from the car body to minimize the adsorption of dust due to static electricity. 2. Rinse promptly after rain: Raindrops on the car body will gradually shrink, increasing the concentration of acidic substances in the rainwater. If not rinsed with clean water promptly, the rain spots can damage the paint over time. 3. Avoid exposure to direct sunlight: When washing the car, wait until the engine has cooled down. Avoid washing the vehicle under direct sunlight or high temperatures to prevent the cleaning agents from drying out and leaving marks. 4. Use clean and soft cloths or sponges for wiping: Avoid mixing in metal shavings or sand particles. Do not use dry cloths, dry towels, or dry sponges to wipe the car to prevent scratches.

I also encountered the issue of dull surfaces when using automotive sandpaper for polishing before, mainly caused by using sandpaper that was too coarse or incorrect polishing techniques. The car paint surface is originally very smooth, and coarse sandpaper can leave fine scratches that make the gloss disappear. To fix this, first prepare finer wet sandpaper, such as 2000 grit or higher, and gently sand the entire area with water to smooth out the coarse scratches. Then, purchase a bottle of automotive polish and carefully apply it with a soft cloth or polishing machine to remove any remaining scratches. Finally, apply car wax to protect the paint surface. The whole process requires patience—avoid applying too much pressure to prevent damaging the base coat. If you're not confident in doing it yourself, taking it to a professional detailing shop is a good option, as they have professional equipment to get the job done quickly. Regularly waxing your car after washing can prevent paint damage, saving both money and hassle.

I often DIY car paint jobs, and dull sanding is a common issue. It's usually due to using the wrong sandpaper or over-sanding. The fix isn't hard: First, use finer sandpaper (1500 grit or higher), wet it, and sand slowly and steadily. Then apply polishing wax and use a low-speed rotary polisher to gradually restore the shine. The final step is applying protective wax. Don't rush—the whole process takes about 20 minutes. I recommend testing on a small area first. You can easily buy common tools like professional sandpaper and polishing paste online. Learn from this: Next time you remove scratches, start with fine sandpaper and wear gloves to protect the paint, avoiding repeat mistakes.

Dull car paint after sanding can be easily fixed in a few simple steps. Prepare fine-grit water sandpaper and car polishing compound. Wet the fine sandpaper and gently rub the entire surface to remove rough marks. Then apply the polishing compound evenly, let it sit for a few minutes, and buff with a clean cloth. Finally, apply wax. Don’t take too long during the process to prevent the paint from getting damaged by the sun. Tools are easy to find, such as kits available at grocery stores. For regular paint maintenance, use neutral car wash soap and a soft cloth to avoid future issues.


