2. The gun speed is too slow and the spraying is too thick at one time.

3. The coating construction viscosity is low.

4. The construction environment temperature is low and the paint drying time is slow.

5. When spraying by wet-to-wet process, the interval time is too short.

6. The spraying pressure is lower than the process range, and the diameter of the spray gun is too large.

(1) Too much thinner makes the viscosity lower than the normal construction requirements, and the paint cannot fall and flow on the surface of the object.

(2) The temperature in the construction site is too low, the drying speed of the coating is too slow, and the fluidity in the film formation is large.

(3) The selected paint brush is too big, too long and too soft, or it is dipped in too much oil and painted too much, so that the thickness of the paint surface varies, and the thicker part will flow.

(4) The brush surface of the object is uneven or the grooves with edges and corners and line angles are easy to cause uneven brush coating and different thicknesses; (5) The paint surface is not clean, and there are dirt such as oil and water. After painting, it is not attached well and hangs.