How to Repair Paint Cracks?

[DeAsher]

Paint cracks can be repaired by: 1. Polishing and waxing for minor cracks; 2. For more severe cracks, the entire area of the paint film needs to be sanded down until a smooth surface is exposed, followed by repainting. Paint cracks are usually very fine at the early stage but will gradually penetrate the paint until reaching the color coat layer. By the time they become visible to the naked eye, the damage is already quite severe. Prolonged exposure to sunlight is the main cause of shortened paint lifespan. Ultraviolet rays from the sun eventually lead to oxidation of the car's coating. If water droplets remain on the car body while it is exposed to sunlight, the oxidation process accelerates significantly. For minor oxidation, wax can be used to remove it. However, once oxidation becomes severe, grinding and polishing are necessary.

[DelBrielle]

Last time I noticed fine web-like cracks on the car door, which was really worrying. Master Zhang from the auto repair shop told me there are several ways to deal with different types of cracks: if it's just the clear coat layer that's cracked, you can smooth it out with 2000-grit sandpaper and then respray a new clear coat; if the crack reaches the base color layer, you'll need to sand off all the old paint in that area and reapply primer and base color. My old car had the entire hood repainted, which cost 800 yuan. The mechanic specifically emphasized that after painting, the paint needs to be baked dry, and it's best not to wash the car for three days. Now I always try to park in the shade and regularly wax the paint surface for protection, otherwise the plastic parts around are particularly prone to cracking after sun exposure.

[LaNorah]

I've been in automotive painting for nearly a decade. Dealing with cracks mainly depends on their depth and area. Small hairline cracks can be resolved with simple sanding and polishing, but for large radial cracks like those at windshield edges, the entire paint layer must be completely removed and redone. Water-based paint repairs are currently popular, involving a five-step process: masking and protection, old paint sanding, filler application, three-layer spraying, and infrared baking. Special attention should be paid to plastic parts like bumpers – plastic primer must be applied first, or the adhesion won't be sufficient. Work must stop if ambient humidity exceeds 70%, otherwise the paint surface may blister.

[MadisonMarie]

Don't delay fixing paint cracks! My best friend learned the hard way when her car developed white streaks near the side mirror that she ignored. Eventually, rainwater seeped in during monsoon season, rusting through the metal panel and tripling the repair costs. Small cracks can be DIY-treated: Clean the area first, then gently dab touch-up paint along the cracks using a pen applicator. Let it cure completely before sanding smooth. However, extensive spiderweb cracks require professional spray booth treatment—standard touch-ups won't last three months. Post-repair, adopt good habits: Apply carnauba wax monthly and avoid automatic car wash rotating brushes that can scratch fresh paint.