High temperatures pose serious challenges for automotive paint application in summer season. Excessive heat accelerates solvent evaporation, often leading to defects such as orange peel, dry spray, and loss of gloss, all of which significantly affect car coating quality. How can technicians overcome these environmental factors to ensure a high quality finish?
1. Adjusting Work Schedule and Environmental Conditions
During hot seasons, properly arranging work hours is crucial. It is recommended to schedule spraying operations during the cooler hours of early morning or evening, while avoiding peak heat periods between 10:00 a.m. and 3:00 p.m. To lower the temperature inside the spray booth, the following measures can be adopted: Use water curtain or mist cooling systems; Keep the floor surface slightly wet to reduce temperature through evaporative cooling; Install thermal insulating curtains to reduce direct sunlight exposure. Importantly, the application environment should be maintained at 25 - 32°C, with relative humidity between 50-70%.
2. Material Preparation and Parameter Adjustment
Materials require targeted adjustments in high temperature conditions. A slow evaporating thinner should be used to extend the coating’s open time. All paint materials should be stored in a cool place, and the paint temperature should be brought down to 20 - 25°C before use.
Regarding mixing ratios, the car paint thinner proportion may be increased by 5–10%, without exceeding the maximum dilution ratio specified by the product manufacturer. It is essential to adjust the formulation dynamically based on temperature changes and establish a set of application parameters for key temperature points such as 25°C, 30°C, and 35°C.
3. Optimizing Application Techniques
Adjusting auto paint spraying techniques is equally important. A “thin coats, multiple layers” approach is recommended, with each coat applied at intervals of 3-5 minutes.
Suggested spray gun adjustments include: Slightly increasing the nozzle size (recommended 1.5-1.7 mm); Reducing air pressure by 0.5-1.0 bar; Increasing spray distance by 5-8 cm. In terms of application sequence, perform sectional spraying rather than covering large areas at once. Keep each section within 0.5 m². Always inspect the coating from multiple angles to ensure an even, wet appearance.
4. On Site Emergency Handling
When signs of overly fast drying appear, prompt corrective actions are essential. For orange peel, immediately apply a blending solvent; For dry spray, stop the spraying at once, sand the affected area, and reapply.
It is advisable to have portable cooling devices such as misting fans on hand. However, ensure that water mist does not come into direct contact with the paint surface. A rapid response mechanism should be established so that abnormalities are addressed immediately to prevent further defects.
5. Post Application Maintenance
Post application coating care is equally critical in high temperatures. Flash off time should be extended by 20-30% compared with standard conditions. Bake temperatures should be reduced by 5-10°C, with the corresponding bake time extended. Ensure the car coating is fully cured before polishing, waiting at least 24 hours is recommended. Additionally, protect the freshly painted surface from direct sunlight.
By implementing these systematic measures, the challenges of high temperature car painting can be effectively managed. The key lies in establishing a temperature monitoring system, equipping proper cooling tools, and adjusting application parameters as needed. The recommendations in this article are general guidelines. Always refer to the technical data sheets of the specific products being used. Conducting a small scale test beforehand is highly recommended to ensure suitability.
