In the process of coating construction, sometimes the old paint layer on the surface needs to be removed and repainted to ensure the flatness of the new coating and achieve the best effect. How to remove all or part of the old paint layer? The following small editor will explain in detail the method of sand blasting (sand blasting) to remove the old paint. The method uses compressed air, high-pressure water flow and mechanical centrifugal force to spray abrasive, sand and metal bullets on the old paint surface, and remove the old paint by impact and friction. This method can also remove the corrosion on the metal surface, but because sand particles and metal bullets will damage the base materials such as aluminum and plastics, metal bullets cannot be used on the components of the above base materials. Recently, with the emergence of plastic sand balls, the surface of almost all substrates can be de painted by sand blasting process.