Many varnishes need to be polished after a certain period of time after brushing. The surface coated with varnish is polished with fine pumice powder and forest cloth; but the surface must be wiped clean with a vine water sponge. This way The result is a smooth and matte painted surface (relevant instrument: gloss meter). Rinse with water after the surface has been sanded, then use a completely cleansing crepe formula.
According to OCT10086-39 test method 23, to determine the sandability of the FA film, use the test panel coated with primer by the following method, use the M-138 primer to coat the test panel, and put the test panel into the constant temperature box for use Dry at 1100°C (related instrument "constant temperature and humidity Chamber"). After the primer is dry, but at least 55 minutes later, take the test panel out of the constant temperature box, and use No. 00 fine paper to polish and remove the primer. Then remove the M-175 putty. Two layers of putty must be applied. The drying time of each layer should not be less than one hour and twenty-five minutes at 110°C. In order to obtain a uniform and matte surface, use a pumice stone powder and water for additional sanding.
If the surface becomes a uniform matte smooth surface after sanding, the varnish can be considered qualified; if there are some small grains left on the surface of the varnish after sanding, or if the surface of the varnish is heated during sanding or If it becomes soft and the integrity of the paint film is destroyed as a result, the clear device is considered unqualified by the book.
The sandability of the varnish can also be measured with a special instrument. In this case, the sanding is carried out by means of a felt or rag with pumice powder instead of pumice blocks. The amount of water used for sanding the surface can be controlled by itself. The sandability of the varnish by volume is expressed by the time required for the varnish surface to reach a uniform, matte smoothness. (Related instruments: Abrasion Tester)
