Will the 4S shop always grind off the entire surface when repainting?
2 Answers
In general, the entire surface needs to be ground off. Here is the relevant information: 1. Reasons for grinding the entire surface: The entire area must be ground off and repainted to avoid color differences, as the new paint is unstable and prone to discoloration or peeling. 2. Impact of repainting on the vehicle: There are roughly two main effects. First, large-area repainting can affect the vehicle's resale value. For example, under the same condition, a car that has been repainted will be cheaper than one with minor scratches but no repainting. Second, repainted surfaces age faster than the original factory paint because the repair paint is not as high-quality as the original. Even if no color difference is visible initially, it may appear over time, and in severe cases, the paint may even peel off.
Not necessarily. I once had a small scratch on the rear door of my car and took it to the 4S shop for repair. The technician checked it and said if it was only surface paint damage without affecting the metal, they wouldn't need to sand the entire panel—just the affected area before repainting, saving both time and money. However, if the damage was deep or there was body panel deformation, they usually sand the entire panel and repaint it to ensure the new paint bonds evenly and to prevent bubbling or color mismatch. Through my conversation with the technician, I learned that color-matching technology is quite advanced now, allowing small repairs to look seamless. I suggest clarifying the extent of the damage before the next paint touch-up—don't worry about always needing a full panel sanding, as the 4S shop will assess the situation realistically. Also, pay attention to regular car paint maintenance, like frequent washing and waxing, to reduce the risk of major repairs. I often wash and wax my car to protect the surface.
