As an inspector I've failed welds that I as a welder am disgusted by and laugh at.
But then for shits and giggles we play in the lab, and what do you know. Ugly but sound. Again and again, and again.
If it meets spec, it passes. And there are some crazy specs, both overly lenient and overly demanding. Some situations you can run a guy off for ugly, other situations the company will run YOU off for failing "perfectly sound" joints and wasting time and money.
I see terrible looking welds on all kinds of dynamic structures whose failure would result in mass chaos. But yet statistically and empirically the failure rates are very low. None of those crappy welds I see regularly have failed and most are exceeding what would be deemed and average lifespan for such a product or construction.
Let the circumstances dictate the level of effort you put into your work.
If it's a rusty muffler on a rusty farm pickup, a little hole patching with the MIG gun ain't nothing but smart, effective use of resources. Why waste the money on new when you've got a shop with the stuff right there to do it in five minutes and get back to making money.
Now if it's a prefabricated pressure vessel, going off to who knows where, and having who knows what running through, in, on, under, over, whatever it is. Point is you don't know what kind of hell or precision environment this thing is going to. So you build it to spec. Every spec has tolerances defined by industry standards organizations and/or governments. Some actually have verbiage about the neatness and appearance, others do not. So again, you build it to spec. Exceeding specifications can be just as undesirable as failing to met them.
shrug
