Am I missing somebody's important detail here, or was the point never made? Isn't there a crucial difference as to the type of welding that can be used to join NON-FERROUS metals like titanium (TIG will do it, as well as aluminum and stainless) and FERROUS metals (MIG, stick, torch-welding will work only on carbon steel and iron, not stainless steel or non-ferrous). That's what I was taught in my Junior College welding class, but then the teacher was checked out most of the time, so YRMV. Here's a thought: back in ancient time (1970's) "Heliarc" welding was what was employed on aluminum, now it's always TIG and Heliarc has faded into history...could THAT be the method used on Teledyne Titans? Alan Goldsworthy San Francisco, CA