Welding Zinc Coated Sheet Metal

Take the proper safety precautions by wearing a welding mask a good welding respirator gloves and an apron.

Welding zinc coated sheet metal.

This results from the variation in boiling points between zinc lower and steel. When galvanized steel is arc welded the heat of the welding arc vaporizes the zinc coating in the weld area. One of the most significant health hazards in the welding process is the generation of fumes and gasses. When you arc weld galvanized steel the heat produced by the welding arc is high enough to vaporize the zinc coating.

Similar to scratched areas of the coating also in the narrow weld the sacrificial effect of the zinc based coating provides cathodic corrosion protection. Coated steels mainly having zinc coatings are readily welded provided that the important factors are understood and the process is set up appropriately. This is because the boiling point of zinc is below the melting point of steel. Welding of zinc coated steel can be done but specific precautions should be taken.

When any fusion welding methods are used the heat input must be as minimal as possible in order to limit the heated zone in the metal coated sheet. When welding zinc coated steel you need to be extra careful to avoid inhaling the fumes. The challenge is welding over the zinc coating. Zinc is the coating used on galvanized metals and when you heat the metal it produces vaporized metal droplets which are called fumes.

The heat of the arc will burn off the zinc coating without problems. The zinc volatilizes and leaves the base metal adjacent to the weld. Do you weld on galvanized metals.