How to Determine if a Car Scratch Has Reached the Primer?

[SadieMarie]

Methods to determine if a car scratch has reached the primer include: 1. Visual inspection—the primer color is opposite to the car paint color, so a scratch will show a noticeable color difference; 2. Run your fingernail over the scratch—if it feels slightly rough and indented, it indicates the primer is damaged; 3. Check if the scratched area has rusted. The main function of the primer is to enhance the smoothness of the car's surface, ensuring the topcoat appears more vibrant and adheres better. Car paint maintenance methods: 1. Promptly remove dust from the car body to minimize static electricity attracting dust; 2. Rinse off rain stains with clean water after rainfall; 3. When wiping, follow the direction of water flow from top to bottom.

[StValentina]

My method for determining whether a car's paint damage has reached the primer is quite straightforward. When there's a scratch on the paint, I first observe the color change; if the exposed part differs from the body paint color, such as showing white, gray, or the metal's original color, it might indicate damage to the primer. I also habitually run my fingernail lightly over the scratch; if I feel a noticeable dent or roughness, as if my nail can catch in it, then the damage has reached the structural layer. Damaging the primer is no small matter; without this protective layer, rain and moisture can easily seep in, leading to rust issues that can corrode the entire car body over time. Once, I ignored a small scratch, and within months, the rust spread to a large area, doubling the repair cost. When washing my car, I take advantage of the light to inspect carefully, especially on parts prone to bumps and scrapes like the front and rear bumpers. If I'm unsure, I simply spray a bit of water to test; exposed primer absorbs water quickly. I recommend car owners develop a habit of regular inspections to prevent minor issues from becoming major ones.

[MariaDella]

I think there are tricks to identifying primer damage. Color inspection is the first step; observe the exposed hue of the scratch. If it contrasts sharply with the topcoat, such as revealing a light or neutral base layer, it indicates deep damage. Next, test the depth; gently run your fingernail over it—if you can feel a depression or step-like depth, it means the primer is exposed. Damaged primer affects rustproofing; moisture intrusion can lead to oxidation, making repairs more troublesome over time. For example, the water spray method: spray some water droplets—if they absorb quickly instead of beading on the surface, it means the primer is exposed. Address it promptly to prevent rust from spreading; I've seen cases where small scratches evolved into corrosion. It's advisable to keep the paint dry and avoid prolonged exposure to humid environments.

[VonMatthew]

To check if the car paint damage has reached the primer, I mainly rely on visual inspection and touch. Observe the scratch; if the exposed area appears significantly different in color under light, such as showing white or light gray, distinct from the body color, it indicates the damage has penetrated through. Run your finger over it; if the depth increases when your nail slides over or you feel unevenness, it confirms the damage level. Damage to the primer exposes the metal, making it prone to water ingress and rust. I often remind myself not to be lazy; timely repair of minor damages can save money and hassle. Maintaining car paint is like caring for skin; prevent dirt and scratches to avoid worsening.