Yes, galvanised steel sections can be welded, but there are important safety and quality considerations. Welding through the zinc coating produces zinc oxide fumes, which are hazardous — adequate ventilation or respiratory protection is essential. The zinc coating will be burned away in the heat-affected zone around the weld, leaving bare steel exposed. After welding, the affected area should be treated with a cold zinc compound or zinc-rich paint to restore corrosion protection. For fabrications that require maximum corrosion resistance, it is often preferable to weld the mild steel first and galvanise the completed fabrication afterwards — this is known as post-fabrication galvanising.
