What causes paint to appear white and cloudy on rainy days? Humidity measures for autumn.
During the long rainy season in autumn, if you paint under the same conditions as on sunny days, the paint film will appear white and cloudy. The cause is humidity and the heat of solvent evaporation. This explains the transition points of the seasons.
Only the items painted on rainy days lack luster and appear whitish. Defects increase during the long rainy season in autumn. ────────────── ■Cause of Occurrence When the thinner in the paint evaporates, it draws heat from the painted surface, causing the temperature to drop. When humidity is high, moisture in the air condenses on the cooled painted surface and is absorbed into the paint film. This results in a white cloudy appearance known as "clouding." ■Truth The cause is that the same thinner and conditions are used as on sunny days. If parts enter the painting area while still cold, it becomes even more likely to occur. ■Improvement Measures It is generally advisable to refrain from painting when humidity is above 85 percent. Switch to a slower-evaporating thinner to prevent rapid cooling of the painted surface. Keep the temperature of the parts at least 3 degrees higher than the dew point, and record humidity and temperature daily. Eiwa Kogei offers baking paint, powder coating, and air-drying paint services. Please download the materials summarizing the key points for process verification and make use of them.
basic information
Defect: Overlapping (whitening). Management items: Humidity, component temperature and dew point, thinner evaporation rate, temperature and humidity records of the painting area.
Price range
Delivery Time
Applications/Examples of results
Seasonal management of metal parts powder coating from autumn to winter, indoor painting booth. Establishing seasonal transition standards for the quality control department and training materials for new employees.
Related Videos
catalog（2）
Download All Catalogs
Distributors
We are not just a "subcontracted painting factory." Established in 1958, our company has a foundation of painting technology and also specializes in chemical treatment, stripping, and cleaning, functioning as the "external surface treatment department" in your organizational chart. Based on our philosophy of "preparation is eight-tenths of the work," we emphasize participation from the "upstream process" before the drawings are finalized. We conduct test painting on a wide range of metals and difficult materials, and we produce the entire process from assembly, packaging, to delivery, thereby reducing your management workload. Additionally, by being able to perform zinc phosphate treatment in-house, we achieve stable painting quality. Furthermore, our micro-heating stripping technology, which does not use chemicals, maintains the electrical state of the "jigs (hangers)" that influence painting quality. Our approach of "pre-treatment determines painting quality" ensures the stability of the paint film during mass production. Rather than simply "applying specified standards," we work backwards to achieve optimal painting specifications and prevent scratches during transportation, sparing no effort in thorough discussions from the outset. This diligent preparation is the shortest path to preventing rework and minimizing total costs. From the development stage, please utilize the expertise of our specialists as part of your production line.