During the coating process, the surface of the paint film bulges in the form of bubbles, or there are bubbles in the paint film. Drying type coatings are prone to this drawback.

The bubbles caused by stirring or the bubbles generated by the evaporation of the solvent do not disappear during the coating film formation process and remain in the paint film, which are collectively referred to as bubbles. Absorbed by the substrate or the primer coating or containing moisture, solvent or gas, the defects of the coating bubbling up in the process of drying (especially drying) are called water bubbles, solvent bubbles or air bubbles, respectively.

Reason:

(1) The solvent evaporates quickly, and the viscosity of the coating is high.

(2) The heating is too fast during drying, and the drying time is too short.

(3) The substrate, primer or coated surface contains (or remains) solvent, moisture or gas.

(4) Paint before the gas mixed into the paint is released by stirring, or the brush moves too fast and air is mixed in when brushing.

Remedy:

(1) If the situation is not too serious, after the paint film is completely dry, sand the wrinkled area with sandpaper, and then re-spray the secondary primer and topcoat.

(2) If the situation is serious, shovel to the bare metal surface for reprocessing.