Prevention and treatment of common quality problems of coating surface of multi-layer coating

1 Concave convex pattern defects: the size of the spots is obviously uneven, there is a phenomenon of contiguity, and the spots themselves have cracks The above phenomena are mainly due to the operator's failure to master the spraying technology of the main coating, the failure to properly coordinate the pressure of the air compressor, the nozzle aperture and the moving speed of the spray bucket, and the failure to properly handle the rolling time and force Prevention and control measures: when spraying the main coating of general multi-layer coating, 6-8mm nozzle with 0.4-0.5mpa spraying pressure shall be used for large spots; 4-6mm nozzle with 0.5-0.6mpa spraying pressure shall be used for medium spots; 2-4mm nozzle with 0.6-0.7mpa spraying pressure shall be used for small spots Of course, these are not immutable They are also affected by the type of main coating, the number of main coating in the spray bucket, the distance between the nozzle and the wall, the moving speed and moving mode of the spray bucket and other factors Rolling time must be appropriate Generally, after spraying the main coating, the surface loses the luster of water, and rolling can be carried out At the beginning of rolling, depending on the composition of the main layer coating and the proficiency of the operator, roll lightly with water or kerosene or other solvents The purpose of rolling with solvent is to prevent the main layer coating from sticking during rolling, and the solvent plays an isolation role in the middle When rolling, do not use too much force, but use even force to flatten the spots, and the height is basically the same 2 Color defects: uneven color and luster Solvent based finish material can be varnish or paint No matter what type of surface material and the way of coating, the surface material shall be mixed evenly and the color shall be the same before coating, and no powder pigment shall be added on site for color matching No brush leakage is allowed during the coating process, and the second coating can only be done after the first coating material is dry.