Blistering of the paint film refers to the appearance of circular protrusions of different sizes—bubbles on the surface of the paint film, and the interior is filled with liquid or gas. This is a phenomenon that the paint film is prone to appear in a high humidity environment, after soaking in water and in the sun.
The reasons for the foaming of the paint film are some of the construction reasons and some of the environmental influences. mainly:
(1) Paint on the base layer that is not completely dry. When the paint film is dry, the solvent or water inside will expand due to heat and bulge the paint film, forming air bubbles. Press the air bubbles with your fingers to feel elastic, and the air bubbles will expand around or break the surface layer under heavy pressure.
(2) Before the putty and primer are dry, the next process is carried out. When the water and solvent in the putty and primer are vaporized, they are covered by the paint film of the outer sheet and cannot escape, forming air bubbles.
(3) When the metal bottom layer is treated, the lake gas accumulated in the pits will be removed, and the bubbles will be caused by local corrosion. In addition to the poor installation of the primer, small air holes are left. When baking, the air expands and pushes up the outer paint film.
(4) When the paint is painted under strong sunlight, the coating is too thick (it is recommended that you use a paint Thickness Gauge), and the surface paint is dried by exposure. After the heat is transferred to the inner paint, the solvent in the paint evaporates quickly. Caused the paint film to blister.
(5) Improper use of paint varieties, such as alkyd enamel paint on the surface of flooding materials; too thick paint film, poor adhesion to the surface, or lack of adhesion between layers; During the drying process of paint, the air in the hole is heated and expands to form bubbles.
In view of the above reasons, the method to prevent the foaming of the paint film is to effectively treat the surface of the object before painting, especially to remove the moisture in the surface depressions and holes; on the porous surface, first apply a thin layer of paint solution , so that the enclosed air can escape in time; the surface coating should use good air permeability latex paint or other architectural coatings; during construction, you should avoid touching the workpiece with sweaty hands; after the workpiece is painted, it should not be placed in sunlight or Under high temperature, and according to the use environment of the paint, the paint variety should be selected reasonably; the paint sprayed or brushed should not be too thick, if you want to get a thicker paint film, you should paint it several times; if there are bubbles in the paint film, you should Depending on the condition of the defect, it is decided whether to repair it locally or to repaint after eradicating it.
