Electrogalvanizing

In hot-dip galvanizing, the workpiece is dipped into a molten zinc bath, forming a solid zinc-iron alloy layer on the surface. That's the core: it's a dipping process, not electrolysis – forget the salt or DC current stuff, that's electrogalvanizing, not hot-dip galvanizing. If you want to weld the part afterwards, you have to completely grind or mill off the zinc layer at the weld seam. Otherwise, the zinc burns, produces toxic fumes, and you get porosity and cracks in the weld. After welding, the area is touched up with zinc spray or cold galvanizing paint, otherwise the weld will rust away.