Do 4S shops grind off the original paint when repainting?
2 Answers
4S shops need to grind off the original car paint before repainting. Here are specific methods to distinguish paint quality: 1. Check the drying quality of the paint film: Press hard on the painted surface with your finger to see if obvious fingerprints appear. If fingerprints are visible, it indicates poor drying of the paint film, and the car needs to be returned to the paint booth for rebaking. 2. Check if the paint color matches the original: In good lighting, carefully observe the repainted area and the adjacent body for 7-10 seconds. Compare the colors by looking straight on and from a side angle (30-45 degrees) to see if there is any noticeable color difference. Note: Dark-colored cars should be compared facing the light, while light-colored cars should be compared with their back to the light. 3. Check the fullness of the paint film and the uniformity of the paint texture: Directly observe the fullness of the paint film. If the paint film is too thick, it may appear cloudy with dull colors; if too thin, the surface may lack brightness with darker colors. A good paint film should appear as if there is a layer of oil floating on the surface.
As a long-time car owner, I've had my car repainted at 4S shops several times, and they do indeed sand off some of the original paint. Why? Simply put, the new paint needs a clean and smooth surface to adhere properly. If they spray directly without sanding, dust, grease, or scratches on the old paint can cause the new paint to bubble or peel quickly. The technicians at the 4S shop use professional tools to first smooth out the damaged area, treating only the necessary sections while preserving the good original paint. The process is time-consuming but not complicated, and after the repair, it’s almost impossible to tell there was any work done—my car has been fine for over a year. I’ve noticed that sanding prevents future rust and maintains the overall condition of the vehicle. In short, this is the standard repair procedure to ensure the new paint matches the original, providing durability and aesthetics for the long term.
