Why there are pinholes when spraying car paint in summer
It is mainly caused by solvents or moisture, which cannot be volatilized when accumulated in the primer layer or topcoat layer.
1. Continuous spraying is too thick and there is not enough drying time.
2. The primer layer has small holes. Before painting, air is contained in the putty when scraping, and the cavities are exposed after polishing, forming small holes.
3. Improper thinner ratio or used poor quality of thinner: If a thinner that dries too quickly is used, pinholes are likely to occur.
4. Surface cleaning or improper treatment: If moisture is left on the surface of the primer, it will evaporate through the surface of the topcoat and produce pinholes.
5. Improper adjustment or technique of the spray gun: Due to improper adjustment of the spray gun, the sprayed paint film is too wet, or the spray gun is too close to the working surface, causing air to enter the paint film, and excessive air or solvent escapes during the drying process to cause pinholes.
6. Insufficient drying after spraying, heating up too quickly during drying, and the surface dries too fast.
7. The temperature of the coated object is too high.
Remedy
1. Grind the paint film to the primer layer, fill the pinholes, spray the primer locally, and re-spray after smoothing.
2. For the pinholes exposed after the putty layer is polished, a thin layer of putty should be coated with a scraper at a 90° angle to the surface to be coated. This ensures that the putty can be pressed into the hole and will not be dragged out due to the movement of the scraper.
