Now coincides with the rainy season, water-based paint construction needs to pay attention to these:
The harsh environment refers to a construction environment where the temperature is below 5°C and the relative humidity is greater than or close to 85%. Take measures to increase temperature and reduce humidity. For example, use 2-3 in the construction room (the specific number depends on the size of the room and the construction area) 1000-2000 watts of lighting (commonly known as “little sun”) to increase the indoor temperature and accelerate the drying speed of the paint film; Conditional can also use dehumidifier dehumidification method and infrared heating method. Thin coating construction. Thick coating should be avoided as much as possible in harsh environments. Thin coating can speed up the drying speed, thereby reducing the probability of problems. Pay attention to the construction time. Under normal circumstances, the temperature and humidity at night are worse than during the day, so construction should be avoided as close to the evening as possible (after 3 pm). After finishing work, the indoor insulation work should be done to avoid opening windows (opening windows can allow outdoor moisture to penetrate into the room and cause paint problems). Pay attention to the construction of the substrate near the outdoor. The doors and windows are relatively close to the outdoors and are easily affected by the low temperature and high humidity of the outdoors. The drying of the paint film is more likely to cause problems, so it is more necessary to ensure the construction of this area and operate according to the above 3 points. Repair and solve problems in harsh environments. Generally speaking, in this harsh environment, it is prone to whitish varnish and white paint cracking. If it still can’t be repaired well, you should make sure that the paint film is dry before sanding off and recoating. For the treatment of cracking, only recoating can be polished off.
2. After the water-based paint is applied, how long should it not get wet?
After the water-based paint is applied, it must not be wetted for at least 7 days. If the temperature is low and the humidity is high, the drying time of the paint film must be extended. When the paint is not dry, there is water splashing on the surface of the object to be coated, and the surface of the paint film is prone to sag; when the paint film is not dry, there is water soaking on the surface of the paint film, which is prone to whitish. With the same principle, the hardness, scratch resistance, heat resistance, water resistance and other properties of the initial paint film have not achieved the best results. Over time, these physical and chemical properties will gradually improve.
3. Why is there whitening on the surface of the paint film after applying the water-based paint?
The phenomenon of blushing is mainly due to the fact that the underlying paint film has not been completely dried and the moisture has not completely evaporated, and it cannot be completely released by covering it. Therefore, the first pass must be hard-dried when painting, that is, to the extent that it can be sanded with sandpaper, the next pass should be applied, and the recoating time at normal temperature is 2-4h. After blushing, it can be directly wiped and repaired with 50% (mass ratio) alcohol. If the effect is not good, you can also purchase dimethylformamide on the market and directly wipe and repair it with 1:1 water, after repairing, under construction A coat of paint; if it can’t be repaired, it can be removed directly with paint remover and then re-constructed.
Therefore, project engineers, supervisors, and persons in charge of construction units need to strengthen management during the construction process to ensure that the working surface of each construction is dry, to avoid the situation where the next process is not performed before the next process.