GregH, Gee all that stuff is completely over my head, in my days they were talking of processes that eliminated the human hand factor. Fusion and other foolproof processes. Around 1960 was talk of welding pipe joints by fusion, claimed was being used even then. In 1955 I was running a submerged arc, solid wire and granular flux, and was told then of gas replacing granular flux. The used flux had a recovery unit, vacuum to separate the dust, but even then could be contaminated with oil etc from the machine its self. That was my first job when I came to the USA helping to build that pipe welder for 12 inch dust collectors, (anti-pollution not a new thing, although many think so) the metal was Corten anti-abrasive. After a few days the superintendent asked me how I was getting along etc. then said to pay attention of the building of the machine as I was to run it when completed.