The high humidity during the rainy season places stricter requirements on automotive paint repair processes. Excessive moisture may lead to whitening, sagging, or adhesion reduction of the paint surface, negatively affecting both the repair quality and durability. As a professional automotive refinish paint manufacturer, we have summarized the key precautions for rainy season application to help you ensure optimal spraying results.
1. Impact of Humidity on car paint repair
• Paint Whitening (Blushing): Moisture mixes with the paint film, causing a foggy or milky appearance, most commonly seen on the clear coat layer.
• Slower Drying Speed: Solvent evaporation rate decreases, extending drying time and increasing the risk of dust contamination.
• Reduced Adhesion: Residual moisture between the substrate and coating layers weakens adhesion, making the paint film more prone to peeling.
2. Key Methods for Effective Humidity Control
(1) Environmental Monitoring and Adjustment
• Use a hygrometer: Ensure ambient humidity is ≤70% before application, with a recommended temperature range of 15–25°C.
• Install dehumidification equipment: Equip the spray booth with dehumidifiers or air conditioning to maintain proper air circulation.
(2) Substrate Preparation
• Thorough cleaning and drying: Use dehumidifying lamps or infrared heaters to ensure the substrate is fully dry.
• Avoid wet sanding: Opt for dry sanding techniques during the rainy season to minimize moisture retention.
(3) Paint Selection and Application Techniques
• Choose fast drying repair coatings: Prefer products designed for high humidity environments to reduce environmental dependency.
• Apply multiple thin coats: Avoid heavy application in one pass. Extend flash off time between coats to allow adequate solvent evaporation.
• Add hardeners or Dry Solution Agent (where applicable): Adjust ratios according to technical requirements to promote faster curing.
3. Post-Repair Maintenance Recommendations in Rainy Season
• Extend baking time: Increase low temperature baking by 10–15 minutes compared to normal conditions to ensure complete curing of the paint film.
• Avoid exposure to rain: Whenever possible, prevent the vehicle from coming into contact with rainwater within 24 hours after repair.
