How To Weld Coat Galvanized Sheet Metal

Welding tips and tricks answer.

How to weld coat galvanized sheet metal.

Take the proper safety precautions by wearing a welding mask a good welding respirator gloves and an apron. Welding galvanized steel is a dangerous task since the galvanized zinc coating on the metal becomes extremely toxic when it s heated. If you attempt to weld galvanized steel without removing the galvanizing from the weld area the weld puddle will pop blow out and create a health hazard to the welder and any individuals in the immediate area. When galvanized steel is arc welded the heat of the welding arc vaporizes the zinc coating in the weld area.

In general the galvanized coatings after fabrication are thicker than the recommended amount and become critical to weld. The best way to weld galvanized steel regardless of welding process is to remove the zinc coating from the joint. Proper precaution is needed when handling these coated metals as their fumes can lead to serious conditions like the metal fume fever. For example i worked for a while welding big tables that held furniture stripper chemicals.

Welding galvanized steel is an important and valuable technique in the metal fabrication process especially when producing galvanized steel wire cloth or galvanized steel gratings but people are shying away from it lately due to the toxic fumes that welding galvanized steel produces. It depends on what you are welding and how critical the application. Tig welding sheet metal. You are right about removing galvanized coatings sort of.

This results from the variation in boiling points between zinc lower and steel. They were made from galvanized sheet metal and we didnt clean crap. The sheet metal can be welded without removal and with a little damage to the zinc coating. Galvanized steel welds similar to uncoated carbon steel when properly prepped.

We just welded em. Forget the larger 1 8 inch tungsten electrode and use a smaller one. Removing the coating and re spraying or painting the weld seam after welding to regain corrosion resistance. Don t attempt to weld thin materials like sheet metal with flux cored wires which put more heat into the base metal.

To weld sheet metal with solid wires use electrode positive ep or reverse polarity. The continuous hot dip or zinc coated sheet comes in eight classes based on the thickness of the zinc coating. In some cases the latter is done regardless of whether or not the coating was removed prior to.