I have had a Trailblazer 440 with a water cooled tig for many years. A few years ago I bought a Miller 350 with a water cooled torch because I was frustrated with getting bird nests in my Millermatic 251 with push pull. But tig is just too slow to suit me. I bought a Millermatic 212 with a spoolgun last December and I think this is the way for me to weld aluminum. I use ER5356 alloy. Cornhusker 800 builds hopper trailers with a trip dump that I designed back in 1992 for me. The prototype is still in daily service and I added 3 more to the fleet last year. Cornhusker does all of their welds with wire. If they use wire to build them, I see nothing wrong with wire to repair them. I am beginning to think I wasted about $8,000 on buying the tig equipment because all it has done is collect dust since I bought my last spool gun. I don't fix airplanes, but I have owned and maintained a fleet of trucks for over 50 years.
