Why should I paint the whole surface of the car for minor scratches?

Why should I paint the whole surface of the car for minor scratches?

Small scratches are common when the car is parked in the open air and running on the road. The car paint is only scratched a little. Why should the whole surface be painted? Can you just touch up the paint where it is scratched? Did the repair shop and 4S shop deliberately expand the paint area for maintenance in order to make more money?

Let's find out why.

1. Prevent the layer boundary of new and old paint

If the paint is simply applied locally at the scratch location, obvious new and old paint layer boundaries will appear as time goes by. As we all know, the old car paint will turn yellow when exposed to wind, sun and rain for a long time, and the yellowing speed will slow down as time goes by. The new paint is close to matching the color of the old car paint through complex fine-tuning technology. On the basis of this color, the new sprayed car paint will also start to yellowing, and the yellowing speed is faster than that of the old car paint. The two kinds of paint surfaces are assembled on the same board, and the difference in yellowing speed will easily lead to the generation of the new and old paint layer boundary, which is not conducive to the beauty of the car paint.

2. Ensure smooth and flat

The whole paint repair process includes multiple links such as sheet metal repair, plaster repair, polishing, primer, color paint, varnish, baking, polishing, etc. It is obviously impossible to polish with abrasive paper. Only the places that need to be painted can be polished accurately. The whole surface can be polished to ensure that the entire surface of the paint is smooth and flat.

3. Reduce color difference

Because the car body paint surface is often exposed to the wind and the sun, the color of the car paint will age and discolor. It is difficult to adjust the color of the car paint to be consistent with the color of the car paint. The interface between new and old paint is very difficult to handle, and color difference is easy to occur without making the whole piece.