I have time on my hands these days so I bought a Mig/flux welder. I have no idea what I’ll do with it but I always wanted one. The machine allows welding with wire that has a flux core or with a gas “shield. Presumably the gas or flux prevents oxidation of the metal when heated. The question I have is that when gas is used with solid (no flux core) welding wire you are directed to connect the wire to the positive terminal and the material to be welded is connected to the negative terminal. When using flux core (no gas) wire you must reverse the polarity. I haven’t used gas but incorrect polarity with the flux wire makes it much harder to get a good bead started. I can’t think of a good reason why the polarity would matter. Anyone have a thought?