What difference is there between GMAW MIG and flux core welding with gasless wire?
(top) With the gasless flux core wire, no cylinder of shielding gas is required. The welds produced with the gasless wire are covered with a protective layer of slag. Typically the spatter level is elevated. The gasless flux core wire welds easier on dirty rusty material whereas a MIG under the same conditions will produce porosity or pin holes. The smallest diameter of gasless flux core wire available is .030 inch or 0.8 mm. The smallest diameter of MIG wire is.023 inches or 0.6mm and you can weld at lower amperage with the smaller diameter MIG wire so it is easier to weld thin material such as auto body steel. Be certain to select the proper welding polarity for the wire you are using. GMAW (MIG) wire use DC+ (electrode positive) and Gasless FCAW wires typically run on DC- (electrode negative) polarity. Selecting the wrong welding polarity will result in an extremely harsh arc with excessively large spatter.
