Attentions, Easily occurred problem and precautions for low-temperature application in Winter
Attentions for application in winter
After the solar term of lesser snow the weather get colder and colder. In cold winter, the temperature is low. During coating application, a series of adverse factors in winter shall be avoided:
1) Treatment of substrate
Wood: Select planks with lower water content. Typically, the water content of planks shall be lower tan 12% and 10% if possible. Protect the planks bought to avoid moisture which will increase its water content. Planks in better condition shall be dried before application to avoid whitening and cracking after application due to the water content of the planks.
2) Use of tools
If air compressor is used in winter, oil-water separator must be installed to prevent adverse effect of oil and water in the compressor to the paint film. Drain the oil and water in the compressor every day to avoid them mixing into the coating and cause bubbles on film surface.
3) Use thinner correctly
During coating application in winter, attentions shall be paid to the difference between winter products and summer product. Due to the difference between winter and summer, the selection of the right thinner is very important. In winter, the thinner used is quickly-dried. Therefore, thinners designed for summer cannot be used in winter; otherwise, the slow drying process will cause paint film faults like lifting.
4) The application environment
In winter, the temperature is low and it is not appropriate to apply coating in low temperature because the performance of chemical materials will have some change. Coating is made of many chemical materials, and attentions shall be paid to avoid a series of adverse factors in coating application in winter.
1. During coating application in winter, the outdoor temperature for application shall not be lower than 5℃, and the humidity shall not be higher than 85%. Therefore, winter application usually will not happen in the morning (because there is water mist or ice fog on the surface of work piece in the morning and the paint film will easily fall off). The application time in winter is usually after 10:00 a.m. Moreover, outdoor application shall not be conducted when it is raining or snowing. The indoor application temperature usually cannot lower than 10℃, and to ensure the volatile of noxious gas and the paint film is dry, windows shall be opened for ventilation purpose after application.
2. In winter, the temperature is low and it takes longer for the paint film to be dry, and the paint film contacts with the air for a longer time. The dust in the air will easily adhere to the paint film surface, causing granule (it is worse with dry air). Therefore, to have better paint film effect, attentions shall be paid to cleaning the environment before coating application.
5) Application method
1. Do not apply coating before the coat is not fully dried or polished to avoid lifting and falling off.
2. Do not apply thick coat at one time to avoid lifting, whitening, cracking, pinholes, blistering and other faults.
3. Do not place the ready paint for too long as its gloss will be reduced.
4. The temperature of coating varies with the temperature of the environment and its viscosity will be higher if the temperature is lower, resulting in using more thinner and the gloss and buildiness of the coating will be reduced. For a better application effect in the winter, keep the temperature of work piece, the paint and the environment to be around 20℃; otherwise, the paint film won't be ideal.