Why is the repainted car paint soft?
3 Answers
The reason why the repainted car paint is soft is that it takes a long time for the repainted car to reach its final hardness, which is why the original factory paint feels "harder" than the repainted paint. Below is relevant information about car paint: 1. Definition: Paint is a chemical mixture coating that firmly covers the surface of an object, serving purposes such as protection, decoration, marking, and other special uses. The authoritative book "Paint Technology" in China's coatings industry defines it as follows: "Paint is a material that can be applied to the surface of an object through different construction processes, forming a solid film that adheres firmly, has certain strength, and is continuous. This film is commonly referred to as a coating film, also known as a paint film or coating." 2. Composition: Paint generally consists of four parts: film-forming substances, fillers (pigments), solvents, and additives. Depending on performance requirements, the composition may vary slightly, such as clear paint lacking pigments or powder coatings not requiring solvents.
The newly sprayed car paint feeling soft is a normal phenomenon, mainly because the solvents in the paint haven't fully evaporated yet. After painting, the paint contains thinners and resin components, which require time for the solvents to slowly evaporate. During this stage, the paint surface appears soft and elastic. Unlike factory paint, which is hardened using high-temperature baking ovens on the production line, repainted surfaces usually dry at room temperature, which is much slower. Higher temperatures can speed up this process, but too high a temperature may cause cracks; excessive humidity can also slow it down. From my friend's auto shop, I learned that good painters know how to maintain a suitable environment and recommend letting the car sit for at least a day or two after painting to allow it to dry thoroughly. Avoid rushing to wipe it with a cloth or wash the car, as this can easily leave fingerprints or scratches. The principle is similar to not touching wall paint before it dries—just wait, and it will become firm.
The root cause of soft post-spray car paint lies in insufficient curing. After the paint is applied, the water and organic solvents need to evaporate, a process that requires patient waiting; if the car is rushed out of the shop too soon, the paint layer won't have a chance to harden. For instance, in winter, the paint takes longer to dry in cold weather, and it might need to stay in the garage overnight; in summer, it may harden too quickly, which can also cause issues. Having handled multiple paint jobs, I always remind car owners to be patient—avoid touching or covering the soft paint to prevent adhesion of impurities. Professional shops use infrared lamps to aid drying, but this step is often skipped in DIY spraying. Once fully cured, the paint naturally hardens, and the factory-level hardness is due to baking. Keeping this in mind helps avoid misjudging the paint job as poor quality.
