1. To avoid scratches and burns on the surface of the workpiece, special care must be taken when polishing with #1200 and #1500 sandpaper. It is therefore necessary to load a light load and use a two-step polishing method to polish the surface. When polishing with each type of sandpaper, it should be polished twice in two different directions, with each direction rotating between 45° and 90°.

2. When using different types of sandpaper, the polishing direction should be changed from 45° to 90° so that the stripe shadows left after the polishing of the previous model can be discerned. Before changing different types of sandpaper, the polishing surface must be carefully wiped with a cleaning liquid such as 100% pure cotton and alcohol, because a small amount of sand remaining on the surface will destroy the entire subsequent polishing work. This cleaning process is equally important when polishing from sandpaper to diamond polishing paste. Before polishing continues, all particles and kerosene must be completely cleaned.

3. Polishing with sandpaper requires the use of soft sticks or bamboo sticks. When polishing round or spherical surfaces, the use of cork sticks can better match the curvature of the round and spherical surfaces. The harder wood, like cherry, is more suitable for smooth surface polishing. Trim the end of the wood strip so that it matches the shape of the surface of the steel piece. This avoids the deeper scratches caused by the acute angle of the wood strip (or bamboo strip) contacting the steel surface.