Causes and solutions of foaming

Blister is a common defect of paint coating. Sometimes it is dry, sometimes it is liquid. Bubbles are large and small, and are hemispherical in shape. The size is usually related to the adhesion strength to the substrate or the bonding strength between coatings and the pressure in bubbles or blisters.

Direct sunlight

Exterior wall paint is applied to the surface heated by direct sunlight.

Wood treatment is not satisfactory.

The substrate treatment is not satisfactory, such as the high moisture content of wood, or the rosin and aromatic oil contained in wood itself have not been removed, which leads to foaming when it volatilizes naturally.

Humid environment

Latex paint is exposed to dew, moisture or rain soon after drying, especially when the surface pretreatment is not enough.

Rainwater enters the coated substrate.

When the outer coating base material is not completely dried, the coating layer or the coating surface layer is destroyed, resulting in rainwater entering the coating base material until the coating base material is wet, and the water stored in the coating base material is thermally expanded under the heating condition in sunny days to form hot air and released outwards until the coating surface layer bubbles.

The doors and windows are not sealed properly.

There is water in the compressor and air pipe, or water splashes on the construction surface.

Eliminate water sources

If the air bubbles continue to reach the base material, we should find ways to eliminate the water source, repair the loose joint filler, and consider installing an exhaust fan to eliminate the air bubbles.

Scrape off bubbles

If the air bubbles do not extend to the base material: scrape off the air bubbles, then polish them, prime any wall surface, and finally repaint the high-quality exterior paint.

Wood treatment

Wood should be dried to a suitable moisture content, and aromatic oil or rosin in wood should be removed.

Coating structure

The construction viscosity of the coating should be appropriate. Don't drag it back and forth when brushing, first straighten it horizontally, then vertically, and finally straighten it along the grain direction.

Regular drainage

Drain the water from the compressor regularly and install an oil-water separator.

repair

For those with slight air bubbles, after the paint film is dried, it can be polished with water sandpaper before adding topcoat. For serious bubbles, first pick them out, carefully polish them with sandpaper, and then repair them layer by layer according to the painting process.