Originally Posted by
mstateglfr
I have both read and been told that pretty looking welds are nothing more than vanity and don’t necessarily speak to the structural quality of the welds.
As a general statement, that's not inaccurate; a pretty weld also needs to be structurally sound. But it's a huge overstatement to say they are "nothing more than vanity...." In almost every case, a good weld will also be pretty. The welders I've known take great pride in making their welds clean and pretty, as well as structurally sound.
On a bike, they are a sign of craftsmanship. Bike tubing is very thin, and the frame needs to be straight, so the whole process matters, the welding sequence along with getting the heat and fill right. It's not a job for beginners. The best welders can make a fillet so small you that paint will almost make it disappear. (That is, not coincidentally, also the strongest weld on thinner tubing.)
Problem is, how are you going to know? On a bike frame, the structural quality is mostly hidden. You have to strip the frame of parts to check, and you still won't be able to see everything.
In any case, I think good craftsmanship is better than bad, and pretty that works is better than ugly that works. I think of such a weld as the TIG equivalent of a filed lug and a clean shoreline.
As far as the OP's question goes, I would look to handmade American frames as reference points, the same way I'd expect Taiwanese builders did. Take a look at late '80s/early '90s Bontrager, Salsa, Fat Chance, etc. if you really want to see how it's done.