FCAWGalvanized and coated steels are frequently welded and flux cored wires are often used for this purpose. Standard MIG equipment is suitable, and the wire composition is chosen to closely match the parent steel. The consumable wire used may be of the basic type or rutile type. Basic flux cored wires tend to give less porosity than the rutile types and so tend to be used more frequently. However, the slag can be very difficult to remove depending on the particular coating being welded. Argon-20%carbon dioxide or pure carbon dioxide may be used as shielding gas. The main problems with galvanized plate are porosity, particularly in the roots of fillet welds, possible cracking, spatter, and zinc oxide fume. With other coatings porosity and spatter can be serious problems and fume from some coatings may be toxic. The main safety issues are potentially toxic fume, electrical, radiation, spatter, and compressed inert gases.
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