What Causes Small Bubbles on Car Paint?
3 Answers
Reasons for small bubbles on car paint: 1. The paint film is sprayed too thick, or inappropriate hardeners or thinners are used; 2. Incorrect spray gun nozzle (aperture), spraying viscosity, or spraying air pressure; 3. Insufficient standing time before heating and drying or inadequate airflow in the paint booth. Car paint is a protective film sprayed onto vehicles, serving as a type of coating that makes the car body less susceptible to corrosion and enhances its aesthetic appeal, with different paints offering varying effects. The main characteristics of car paint performance include excellent film fullness, high gloss, high hardness, good adhesion, and superior mechanical properties.
Small bubbles appeared on the paint of my old car because I didn't dry it after washing and left it exposed to strong sunlight. The moisture trapped under the paint expanded when heated, causing bubbles. Another time, I parked under a tree, and tree sap stuck to the car. Not washing it off in time corroded the underlying paint. If there's dust or unevenness in the paint layer, trapped air during painting can also cause bubbles. Underlying rust is another common issue, especially when rainwater seeps in and corrodes the metal over time, lifting the paint. To avoid these problems, regularly wax the car to protect the paint and park in shaded areas. If repainting, let professionals handle it to avoid DIY mishaps. Paint bubbles aren't just unsightly—they accelerate aging, so address them promptly to prevent further damage.
As a car enthusiast, I've done several paint repairs myself and found that small bubbles often result from painting mistakes. For example, rough sanding leaves dust, trapping air bubbles during spraying; or applying a new coat before the previous one dries completely, trapping moisture that expands. Low-quality paint is prone to bubbling under sunlight, and corrosive substances like acid rain can also damage the paint. I recommend using high-quality spray tools and applying thin layers, ensuring each layer dries thoroughly before continuing. When washing the car, use mild detergents and avoid excessive force to prevent damage to the underlying layers. Proper paint maintenance reduces UV damage and extends its lifespan. Regular inspections and early fixes for minor issues can prevent major repairs.
