I've seen guys who weld aluminum day in and day out with the new mig machines and yeah, pretty awsome looking watertight welds to say the least.
Like someone said earlier in this post theres a place for mig and theres a place for tig.
But absolutley nothing wrong with tig welding whatsoever. You can tig anything, however it takes alot longer. That's why I was shocked when I had that discussion. But hey if people want to tig or mig their crafts then hey, that's their choice. Either way, I'm sure it's going to turn out nice when people know what their doing.
Some boat builders like the 3 I mentioned on van island are building boats to a commercial standard. Which means the struts, bracing, ribs, however they are designing the structure in the boat is welded heavy, not just 4 inch stitch welds a foot apart. Like most of the silver streaks I've seen roll throught the shop. We have rewelded a few for not enough welding and the result is they crack. The biggest thing I have seen with those particular boats is that they not only stitch weld fsr apart, the silicon in between the stuch welds with gray silicon. This makes it a real pain in the butt, when it comes to repairing the welds. Have to scrape it all out and clean it and it's a challenge to say the least.
Production boats like thinderjet, hewes, north river etc etc are another topic all together. Thunderjet actually uses a one piece bottom on most of their boats. Which is very strong. Hewescraft does 2 piece with an extruded aluminum strip to join the 2 halves. On the bigger models they weld an angle right over this under the boat and its solid welded. Which is strong. The smaller hewes just use the strip of extruded, which always cracks. Same as the north river boats. Not sure about northrivers bigger platform.
Fiberglass is better lol