The Correct Posture And Precautions Of The Grinding And Polishing Process After Car Paint Film Repair
A. Clean the whole vehicle
First of all, before grinding, clean the whole vehicle with dewaxing car wash liquid or paint cleaning agent with strong detergency to completely remove the dirt on the paint surface, but do not need to dry it, and at the same time, avoid new scratches caused by particle dust during grinding.
B. Water sandpaper repair
For defects such as coarse grains, fine sandpaper marks, or sagging marks on the sprayed surface, use No. 1000~2000 water sandpaper dipped in water and wrap it on the outside of the tiny rubber pad before polishing, and gently polish it until it is smooth (be careful not to wear through) paint layer). If there are no traces, you can go directly to the grinding process.
C. Coarse and fine wax grinding
Use an electric grinder to add coarse wax to grind the traces of waterproof sandpaper, and then add fine abrasive paste for polishing and fine grinding. The method of operation is described below.
(1) Soak the sponge head with clean water, and apply coarse and fine wax (thick first, then fine) on the sponge head of the grinder, or directly on the car body paint surface that needs to be polished.
(2) Gently press the grinder switch above the paint surface of the car body that needs to be polished, and the wax will be evenly coated on the paint surface of the car body that needs to be ground under the action of centrifugal force.
(3) Grinding operation skills. Before grinding, the machine should be turned on first, and then the grinding and polishing machine should be gently and slowly placed on the paint surface, and the pressure should be gradually increased evenly to prevent deep halo marks caused by instant contact. When the grinding is nearing the end, the force should become lighter and lighter, and finally, gently start on the working surface to prevent halo marks that cannot be removed by the next polishing process after grinding. During the construction, the machine head should try not to leave the working surface and should move back and forth in a straight line at a constant speed, and the second track should be pressed against 1/3 of the first track, and at the same time, it should be carried out alternately up and down according to the size of the plate. There should be no interruption in the whole process. It was done in one go. After grinding, the paint surface should be matte. If it is found that the brightness of some parts is different from that of other grinding parts during the inspection process, the brightness is better, and there is no grinding mark, it means that there is a phenomenon of missing, and it should be repaired in time. Take remedial measures, spot grinding, or hand grinding.
(4) Precautions for grinding operation. The grinding process cannot be carried out in a dry environment, so there is no need to wipe off the water droplets attached to the paint surface after washing the car.
1) During the grinding operation, the grinding head should always be kept parallel to the working surface.
2) Do not grind excessively at the corners of the paint surface of the car body to prevent the surface paint layer from being worn through, because the paint film thickness at the corners is relatively thin.
3) The intensity of grinding should be gradually reduced near the end to prevent halo marks after grinding.
4) After grinding, the car body should be thoroughly washed with car wash liquid and polished.
D. Polishing
There are many similarities between polishing and grinding. The main difference is that the maintenance products used in polishing are finer polishing agents than neutral abrasives, mainly to remove slight oxides and impurities on the surface of the paint layer, and throw away coarse The spin marks left by waxing can fill up the small defects on the surface of the paint film, that is, degrease and eliminate the defects of the paint surface, so that the paint surface can achieve a mirror-like smooth effect and prepare for waxing.
