Generally speaking, the file grinding nozzle is often used on the gundam model to be sprayed, because the gundam model to be sprayed often has to go through several layers of painting operations, such as water repair, topcoat and protective paint, and the paint surface has a certain repair effect on the polished wear marks, so if there are slight wear marks, the effect will not be affected, and the firmness of the paint surface can be strengthened. At the same time, filing is more convenient and faster, so gundam models to be sprayed often choose to use filing.
If the element group is as high as the model, the file will be polished less, because there is no paint to cover the wear marks, so in order not to leave the wear marks, it will be polished with water sandpaper. I usually polish it with water after 800 meshes and then 2000 meshes. Finally, I polish it slightly with polishing paste, and there are basically no grinding marks.
So sandpaper and polishing paste have their own advantages and disadvantages, and each has its own uses, mainly depending on how you make the model.