What problems should be paid attention to in the appearance inspection of coating surface defects

       The surface of the spray coating should be consistent in color, the coating and the corners of the workpiece should be free of oxidation, and the coating thickness should be consistent. The appearance of the spray coating should be smooth and flat, and no condensation and coating peeling are allowed; there should be no defects such as pores, slag inclusions, cracks, and pinholes.



    In order to facilitate the clear observation of coating surface defects and prevent the interference of external factors, visual inspection of coating surface defects should be carried out on the specified visual inspection workbench or visual inspection box.

    When natural lighting is used for the visual inspection work, the sample should be placed on a white platform without reflected light to be inspected by natural scattered light in the forward direction; when artificial lighting is used for the visual inspection workbench and visual inspection box, the illuminance should be 300lx approximate natural light (equivalent to 300lx). Illuminance at 500mm of 40W fluorescent lamp). During visual inspection, the distance between the sample and the naked eye is not less than 300mm. For important coatings and test pieces with special requirements, a magnifying glass of 2 times to 5 times is allowed to be used for inspection.

    For the test piece to be inspected for coating appearance defects, the oil stain on the surface of the test piece should be wiped off with a clean soft cloth or cotton gauze before the inspection, but care should be taken not to scratch the coating.

    During the inspection, the operator should pay attention, carefully observe whether there are various impermissible defects on the surface of the coating, and make a correct evaluation according to the quality and technical standards of the product. The degree of malpractice should be explained in words, and the appearance should be sealed if necessary.