The paint film "laughs", also known as "shrink paint". That is, after the topcoat is applied, the paint film shrinks into jagged, bead-like, speckled spots like water wine on wax paper, which destroys the topcoat and exposes the bottom layer, like the facial lines when people laugh, so it is called "laughing".
The main reason for the "laughing" of the paint film is that the wettability of the paint to the surface of the object to be coated is not good. The methods to prevent "laughing" are as follows:
(1) After dry exercise, if you paint the topcoat without surface treatment, you will "laugh". Such as mild "laughing", when painting the paint, it can be eliminated by repeated brushing. When the "laughing" is serious, you can stop painting the paint, wipe the surface with gasoline or pine perfume, pat the surface with lime powder in a cloth bag, and then clean it up, or brush 1 or 2 times with shellac varnish to seal, that is, Optional exemption.
(2) The paint surface is stained with oil, sweat, acid and alkali, wax, etc., or it is exposed to a lot of corrosion after painting. The "laughing" phenomenon caused by these reasons can be avoided as long as the dirt at the bottom is removed, and smoke-free is selected after painting; , and then repaint Serve.
(3) In the rainy season, cloudy days or in wet places, the surface to be painted will have water mixed in, because oil and water cannot mix, it will also cause "laughing". This is as long as the construction is carried out on a sunny day, and the surface of the object should not be stained with water.
(4) The object surface is too smooth, or the primer is too smooth, and the topcoat cannot be evenly attached. For the "laughing" caused by this reason, generally use a hard brush to repeatedly brush the paint surface alternately vertically and horizontally or diagonally several times, and the "laughing" will disappear naturally. In addition, fine sandpaper can also be used to grind off the luster of the primer, and after a little roughening, it will not "laugh" when it is painted again.
(5) No oil-water separator is used during spraying construction, so that the moisture in the air and the oil inside the Air Compressor are mixed into the paint and sprayed on the object surface, or a very fast volatile solvent (such as acetone) is misused in the spray paint, and the paint The film is too late to level, and the solvent has volatilized, resulting in "laughing". For the "laughing" caused by improper spraying method, after the paint film is dry, add the supporting thinner, slip the layer, and spray it again.
(6) The two-component paint should be stirred evenly during the deployment, and it should be cured before painting. If the epoxy paint appears "laughing", an appropriate amount of strong solvent can be added.
For the "smile" paint film that has dried, use solvent to wash it off and repaint the paint.
