Is it necessary to repair scratched car undercoating?
2 Answers
It is not necessary to repair the scratched undercoating of a car. Here is the relevant information: 1. The difference between original factory paint and repair paint: Both can meet the decorative and anti-corrosion requirements of the car surface, but the construction methods differ greatly. Original factory paint now uses robotic arms for automatic coating, so the viscosity and other indicators of the paint are generally fixed, resulting in high-quality original coating. Repair paint, however, is mostly applied manually, and the coating environment is far inferior to that of the original factory. Therefore, after car paint repair, the quality of the paint film is usually somewhat compromised. Repaired paint is not as good as original factory paint and is prone to fading and flaking, with some areas showing color differences after repair. 2. Repair methods: Large scratches cannot be fixed with car wax. If immediate paint repair is not possible, use toothpaste to cover the scratch to prevent rust. If you have a touch-up pen, use it to repair the scratch by applying it evenly around the area. After the paint dries, reapply car wax to easily remove any residue.
As a mechanic with over a decade of experience, I must emphasize that scratched underbody paint must be repaired. The chassis is the skeletal structure of a vehicle, and that layer of paint primarily serves as anti-rust protection. Once scratched, exposed metal can rust extremely quickly when exposed to rainwater or humid air. What may start as a small spot can spread, compromising the metal's strength. Over time, this can affect suspension components, steering systems, and even the entire frame's safety. I've seen countless cases where owners neglected this issue and ended up paying for major repairs. Especially if you drive a new car or live in rainy coastal areas, timely treatment can prevent big headaches. I recommend first assessing the scratch size - minor ones can be touched up with anti-rust paint yourself; for serious damage, it's best to visit a professional shop for complete rust removal and repainting. Prevention is always better than costly repairs later. Don't assume that just because the underbody isn't visible, it doesn't matter - small oversights can lead to major problems.
