How to weld leaking galvanized water pipes by ordinary electric welding?

According to my years of welding experience with water, first, observe whether it is gap leakage or sand hole leakage. If it is a gap leak, you can use gas welding while baking and welding, and the effect is good. If there is missing welding in the sand hole, fix the nail in the sand hole with an iron file according to the size of the hole to avoid missing welding. If not, drill a hole smaller than the nail with an electric drill. When drilling, block a splint in front of the electric drill to prevent water from wetting the electric drill and the drill bit from penetrating the splint for drilling.