What is the difference between factory paint and 4S shop paint repair?
3 Answers
The differences between factory paint and 4S shop paint repair: 1. Different spraying environments: The OEM paint shop in the main factory is a sealed positive-pressure workshop with air filtered through multiple layers and oil-water separation; 4S shop paint repair is done in a separate paint room or outdoors. 2. Different construction tools: Factory paint uses robotic automatic spraying in the main factory; 4S shop paint repair uses ordinary spray guns for manual work. 3. Different baking methods: Factory paint in the main factory's paint shop uses thermal radiation to bake the car body at temperatures up to 200 degrees Celsius; 4S shop paint repair uses lamp baking.
As someone who frequently performs vehicle repairs, I've found that the biggest difference between factory paint and 4S shop touch-ups lies in the completeness of the process. Factory paint is applied on the vehicle assembly line, undergoing seven processes including 120 seconds of electrophoretic primer and 200°C high-temperature baking, forming perfect adhesion on metal surfaces. 4S shop touch-ups can only be done locally, with baking temperatures not exceeding 80°C to avoid damaging plastic parts, resulting in poor paint layer adhesion. Additionally, factory painting is done in dust-free workshops, while even the cleanest 4S shop environments will have fine particles adhering. These differences make touch-up areas more prone to color discrepancies, cracking, and peeling, especially becoming more noticeable after three to five years. It's recommended to apply crystal coating protection after touch-up painting.
Last time I got a scratch on my car and went to the 4S shop for a paint touch-up, the technician said the original factory paint involves a full-body immersion electrophoretic treatment on the chassis, a step that simply can't be replicated during later repairs. Touch-up paint only does superficial work—even though the same brand's color paint is used, it lacks the high-temperature curing step, resulting in a less dense molecular structure. The most frustrating part is that the touched-up area ages at a different rate than the factory paint. My white car, just two years old, already shows some yellowing on the touched-up sections, while the original parts remain bright white. Additionally, the overall metal anti-corrosion performance of the car is compromised, especially in humid coastal climates.
