As temperatures drop sharply in winter and air humidity increases, higher demands are placed on automotive refinishing operations. Many technicians encounter issues such as slow drying, poor adhesion, whitening of the paint film etc. To achieve ideal repair results under low temperature conditions, it is essential to take a systematic and scientific approach, which is focusing on surface preparation, spraying techniques, and curing acceleration.
1. Surface preparation is the critical first step. In cold environments, metal vehicle panels are prone to accumulating microscopic moisture or oil films. If these contaminants are not thoroughly removed, paint adhesion and coating uniformity will be directly affected. It is recommended to move the vehicle into a temperature controlled indoor area prior to painting and to use degreaser to ensure the surface is completely clean, dry, and free of contamination. After sanding, spraying should be carried out immediately to prevent moisture in the air from reattaching to the surface.
2. During the spraying process, attention must be paid to mixing ratios and flow control. At low temperatures, car refinishing paint viscosity increases, which can lead to uneven atomization or orange peel defects. To counteract this, the thinner ratio should be adjusted according to ambient temperature, or a thinner specifically designed for low temperature applications should be selected to maintain proper paint flow. Spray air pressure can be slightly increased to achieve finer atomization and a smoother finish. Flash off times between coats should also be appropriately extended to prevent trapped solvents from causing whitening or cloudiness in the paint film.
3. Curing acceleration is the final key factor in ensuring coating performance. Low temperatures significantly slow down chemical reaction rates, resulting in extended drying times. When possible, infrared curing lamps or low temperature baking equipment can be used to assist heating and accelerate the curing process. In situations where heating is not feasible, fast hardener can be employed to improve crosslinking efficiency, allowing the paint film to reach the desired hardness and gloss within a shorter time frame.
