How to prevent the appearance of "water droplets" on the surface of the paint base?

The surface of the base layer of the paint will drop down like water droplets, and some areas will have sand-like protrusions. What is going on here? How to prevent it?

Dulux European paint

This is a common phenomenon in paint construction: one is a paint fall, and the other is a rough surface of the paint film.

The phenomenon of paint dripping, sagging, and uneven film on the surface of the base layer can all be referred to as paint drop. The main reasons are: the preparation of the paint is too thin, poor adhesion, some of the paint under the action of gravity flow; paint or spray paint is too thick, the paint film is too heavy; the construction environment temperature is too low, the paint film dry slowly; With too much heavy pigment, some paint drooping; The surface of the base layer of the object is uneven, the thickness of the paint film is not uniform, the drying speed is different, the thick part of the paint film is easy to fall; the oil, water and other dirt on the surface of the base layer are not compatible with the paint. Content, affect the adhesion, resulting in sagging paint film.

So what measures can be taken to prevent paint from falling? First of all, we must choose a good quality paint and a suitable diluent for the volatilization rate, and control the amount of infiltration. Secondly, the surface of the object should be treated as smooth, smooth, and clean the surface of oil, water and other dirt. The ambient temperature of the re-applied construction shall meet the standard requirements for paint types. For example, the varnish shall be applied at 20 to 27 degrees Celsius and brushed within 3 hours. When painting again, it should be carried out according to the procedure: vertical, horizontal, oblique, and then leveling the paint vertically so that the paint film thickness is uniform. When the spray gun is sprayed, the speed of the gun and distance from the object should be controlled evenly. According to the prescribed process procedure, the vertical spray, vertical spray, and lateral spray are used to make the paint film uniform and uniform in thickness.

The surface roughness of the paint film is specifically expressed as the paint is filmed, the surface is uneven, there are sand grains or small bubbles. The main reasons are: too much pigment in the paint or too coarse particles; the paint itself is not clean, mixed with impurities, and used without sieving; the ambient temperature during the deployment of the paint is low, and the bubbles in the paint are not completely dispersed and discharged; The surface is not clean, there are debris and other debris, mixed into the paint film when brushing; use of the holder (brush, paint bucket, spray gun, etc.) is not clean, there is residual debris into the paint; construction environment cleaning and protection is not enough , Dust, sand and other debris in the brush stick to the brush or fall on the paint film.

To prevent the rough surface of the paint film, we also have several precautions: First, we must select a good quality paint, use a fine screen before use, and reconcile evenly, and then use it without bubbles. Next, we must pay attention to the surface of the object clean, keep it flat, smooth, dry. Then, it is very important to arrange the order of construction of various types of works reasonably and ensure that the construction environment for painting is free from sundries and dust. Finally, we must be careful not to repeat the use of different types of equipment with different performance paint, if necessary, the residue should be cleaned before use.

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