First, look at what material it is made of. If it is 20 1, cover the sand hole with a stainless steel strip with a width of 5 ~ 10 cm and the same thickness (depending on the degree of corruption at the sand hole of the water tank), and weld both sides of the stainless steel strip with argon arc welding! It must be the boiler water tank. The temperature is so high. If it is an inflatable boiler water tank, be sure to use thickened stainless steel strips! If it is made of 304 material, it should be welded with 304 stainless steel bar, 308 welding wire or 3 16 welding wire.