How many grids should the solder joints be polished before painting?

The solder joint should be polished to about 800 mesh before painting.

After welding stainless steel, rough grinding should be carried out first to make the weld smooth. A 320-mesh circular grinding wheel is used to remove the convex part left by rough grinding to achieve a smoother surface. Further grinding with a finer 800-mesh circular grinding wheel makes the surface smoother and more uniform. At right angle, the metal sheet is attached at a 45-degree angle, and the tensile test is carried out with a wire drawing machine. There are no problems such as fracture in this process, which shows that the solder joint can be successfully drawn.