Hello All, in my past experiences with the various gas-shielded flux-cored wires 100% CO2 was the fore-runner to accepted shielding gas, then there was the introduction of 75% Ar/ 25% CO2 in some instances, and as of late ESAB has a wire that is designed to be used with 90% Ar/10% CO2. Some of these wires are 100% CO2 only, some are 75% Ar/25% CO2 only, some are either the 75% Ar/25% CO2 or 100% CO2, and now there is the ESAB wire that is designed to be run on the 90% Ar/10% CO2. There may also be others of which I am not aware of yet.
     With all of these wires, there are the claims of the manufacturers as to their specific benefits and performance capabilities. Certainly 100% CO2 shielded wires will be cheaper to run than Argon mixed shielded ones, strictly looking at gas cost. Yet, maybe the clean-up associated with the straight CO2 welding outweighs the additional shielding gas cost. Similarly, there is a possibility that the performance characteristics of the finished weld CAN be met by a particular wire that utilizes the Argon mixed gas wire that CANNOT be met with a 100% CO2 shielded wire.
     In the case of the ESAB wire that I read about, they claim a considerable increase in travel speed and metal deposition on vertical fillets using their wire that shields with 90% Ar/10% CO2. In some instances, if this is true, a given fabrication or welding scenario might justify the additional cost of gas and even a more expensive electrode.
     The bottom line with any wire/gas combination is to have a good appeal for the welders, the proper finished weld performance, and when all the numbers are crunched to have the best dollar to weld laid down ratio. Just my $.02 Regards, aevald