The drying characteristics of nitro paint

Nitro lacquer is a solvent-volatile coating, which can gradually transform the liquid coating into a solid state and form a film through the evaporation of the solvent at room temperature. The remarkable feature is that it dries quickly. According to the "Nitro Paint Standard" and technical indicators, at room temperature of 25°C and 1°C, the hard drying time is 50 minutes. The technical indicators of phenolic and alkyd paints under the same temperature conditions, the hard drying time is 15-24 hours, in contrast, the drying speed of nitro paint is more than 18 times faster. Another characteristic of nitro lacquer is that the paint film is prone to whitish phenomenon when it is dried in wet season or cold weather.

An opaque or translucent milky fog layer is formed on the surface of the transparent coating, which makes the paint film blurred, loses luster and transparency. The reason is that the low-boiling-point solvent in the nitro-lacquer is rapidly oxidized and absorbs a large amount of heat, which makes the air on the coating surface cool down rapidly, and the water vapor in the air condenses on the coating and penetrates into the paint film. If the base paint is incompatible, the paint film will appear cloudy and whitish. In order to prevent the nitro lacquer paint film from spontaneously developing, the doors and windows should be closed at the painting site, avoid direct blowing of the coating, keep an appropriate temperature to reduce humidity, or add 10%~30% medium and high boiling point solvents to the nitro lacquer as a moisture-proof agent, so as to slow down the volatilization rate, reduce the condensation of water vapor, and prevent the whitening of the paint film. Low temperature or infrared preheating can also be used for the painted surface to prevent whitening of the paint film.

After the paint film turns white, wait for the water from the wax to evaporate and disappear (or use a rag to remove it), and then paint the nitro paint with a moisture-proof agent, and the whitening will disappear.