How to Determine if the Primer is Damaged?
2 Answers
Methods to determine if the primer is damaged are as follows: 1. Visual inspection: Primers are usually black, gray, or white, and these colors are generally opposite to the car's paint color. If the car paint is scratched, there will be a noticeable color difference. If the scratch reveals the primer, it can be clearly seen. 2. Use your fingernail: You can also run your fingernail over the scratch to feel for any indentation. If it feels slightly rough with a shallow indentation, it's usually just a surface scratch, and the primer is not damaged. Polishing and waxing will suffice. If the scratch can catch your fingernail, it indicates a deeper scratch, and the primer is more likely to be damaged. 3. Check for rust: Any scratch can potentially rust. If the primer is damaged, the likelihood and speed of rusting will increase. Applying toothpaste can temporarily prevent rust. Gently rubbing toothpaste in a circular motion on the scratch can reduce the scratch mark and act as a simple barrier, preventing rust in the short term, especially for white car paint, where the effect is most noticeable.
I've been driving for nearly twenty years and have encountered numerous scratch incidents. The key to determining whether the car's primer has been damaged lies in careful observation of color and texture. The car body surface is typically the paint layer, with the primer underneath, often appearing grayish-white or dull. If the scratch isn't in the color of the car paint but rather a pale gray or light metallic shade, it's likely the primer has been affected. Gently run your finger over it: if you feel a noticeable dent or roughness, rather than smoothness, the damage has penetrated to the primer layer. Last time I scraped on a gravel road, seeing a whitish color, I knew immediately upon touching it that it was bad. In good lighting, viewing from an angle can also reveal the difference: deep damage is glaringly obvious under reflective surfaces. If left untreated after primer damage, water and air infiltration can lead to rust, significantly increasing repair costs later. I recommend washing and inspecting immediately upon discovery, spraying some water to test—if the water absorbs quickly or causes noticeable color changes, it confirms the severity. Developing a habit of regular maintenance can prevent minor issues from turning into disasters.
