How to Determine if the Car's Primer Has Been Damaged?
2 Answers
Methods to determine if the car's primer has been damaged: When the primer is damaged, the metal layer of the car body is directly exposed to the air. Combined with humid climates, this can easily lead to rusting of the car body. Additionally, noticeable color differences will appear on the car's surface. Applying toothpaste can temporarily prevent rust. Gently rubbing toothpaste in a circular motion over the scratch can reduce the visibility of the scratch and act as a simple barrier, preventing rust in the short term, especially for white car paint, where the effect is more pronounced. The main function of the primer is to enhance the smoothness of the car's surface, making the color paint appear more vibrant and better adhered after application. Car owners can use their fingernail to feel the scratch. If it feels slightly rough with a shallow indentation, it indicates only the surface paint is scratched, and the primer remains intact—polishing and waxing will suffice. If the scratch can catch the sliding motion of the fingernail, it suggests the scratch is deeper, and there is a higher likelihood that the primer has been damaged.
Having driven for over a decade, dealing with scratches is a common occurrence for me. It's immediately obvious when the damage reaches the base coat. For example, when viewed at an angle under sunlight, if the deeper part of the scratch shows a different color, revealing a metallic sheen or grayish material, it's definitely penetrated to the underlying paint layer. I remember the last time my car door scraped against a wall—a light touch revealed unevenness, and running a fingernail over it caught on the groove, confirming it was deep enough to reach the base coat. Some scratches are merely surface marks that can be cleaned off with a car wash, but if the base coat is damaged, leaving exposed metal untreated can lead to rust, especially accelerating after rain. I recommend being mindful to avoid branches or hard objects when parking, and addressing any issues promptly by visiting a repair shop for touch-ups. This prevents minor damage from escalating into bigger, costlier problems that drain both your wallet and peace of mind.
