How to Repair Cracking Car Putty?
2 Answers
Cracking car putty generally cannot be repaired; the best solution is to reapply putty to the vehicle. Methods to prevent car putty from cracking: 1. Choose high-quality filler putty when selecting products. Low-quality filler putty has lower hardness and viscosity, making it difficult to adhere effectively to the car body. 2. Do not add solvents like thinner to the filler putty during application, as this can easily lead to cracking, bubbling, and denting of the paint. 3. Avoid applying putty too thickly. Thick layers of putty are harder to dry and have poorer adhesion. 4. Wait for the putty to dry completely before painting. Painting over wet putty will result in poor paint quality. Note: Car putty does not last a lifetime; it typically lasts only about 3 years.
I've encountered car putty cracking several times, mainly caused by insufficient compaction during repair or drastic temperature changes. The remedy isn't too difficult but requires careful attention: First, use coarse sandpaper to sand the cracked area, thoroughly removing loose particles and dust—leave no impurities behind, so the new putty can adhere properly. After the surface is clean, apply specialized automotive putty, recommending a thin, even layer over the crack—avoid applying too thick, as it may crack again. Once patched, wait patiently for it to dry completely—I usually wait over two hours, depending on humidity—then sand smooth with fine sandpaper, ensuring it's flush with the body. Finally, spray with matching car paint, remembering to apply a primer coat before painting. After drying, wax for protection. The entire process should be done in a ventilated area, avoiding rainy or extremely hot conditions. If the crack is too large or shows signs of rust, it's best to seek professional repair to avoid worsening the damage and affecting the car's lifespan. Regularly inspect the putty layer after washing—early detection and treatment can save a lot of trouble.
