Galvanized steel and carbon steel contain the same base material, steel. The corrosion-resistant zinc coating that covers galvanized steel is the only component that varies between the two metals. When you are welding, the galvanized coating will cause the weld puddle to pop and reduce the quality and strength of the finished weld. Removing the galvanized coating from the weld area will allow you to weld the two metals and produce a high quality, strong weld.
Lay the piece of galvanized steel and the piece of carbon steel flat on top of the work table.
Slide one end of the piece of galvanized steel over the edge of the work table.
Attach the 40-grit flapper wheel onto the 4.5-inch angle grinder.
Put on your welding gloves and safety glasses.
Pull the trigger of the angle grinder and run the spinning 40-grit flapper wheel along the edge of the galvanized steel overhanging the edge of the work table to remove the galvanized coating from the edge of the steel.
Clear all the galvanizing within 1 inch of the edge you cleaned in the previous step. Make sure that you clear the galvanizing from both sides of the piece of galvanized steel.
Slide the cleaned edge of the galvanized steel and one edge of the carbon steel together and pull the two pieces of metal apart 1/16-inch. This will allow for a weld gap in the weld joint.
Put on your welding hood, turn on the MIG welder and turn the valve of the bottle of shielding gas.
Aim the wire protruding from the MIG gun at the 1/16-inch gap in the weld joint and lower your welding hood.
Pull and hold the trigger of the MIG gun for two seconds to tack the two pieces of metal together. Place one tack every 2 inches until you reach the other side of the weld joint.
Place the MIG gun at one end of the tacked weld joint, pull the trigger of the MIG gun and push the weld puddle along the weld joint to weld the galvanized steel to the carbon steel.
Remove your welding hood and allow the weld joint to cool before you handle the two pieces of welded steel.
