Before welding, zinc must be removed during surface treatment, because zinc will release zinc vapor and white powder at high temperature, which is easy to be poisoned after inhalation. When welding, pay attention to keep ventilation. After the galvanized sheet is welded, it is polished to remove welding slag and sprayed with cold galvanized aerosol. For the construction method, refer to the following link (repair by welding repair department): Web page link, click the welding repair drop-down box to view the construction steps.