I got to agree with some stuff here, welding schools can be a **** shoot. My first welding school had instructor that was a crappy welder but he knew a lot about the world of work. I was in a com college a while back where a lot was trial and error with practice, I coached a kid for a few mins and should have seen his eyes light up when someone explained a bit vs go try again. Look for somewhere with hands on teachers willing to demonstrate and can explain. Top schools like Lincoln and Hobart are good at this. Not everyone that owns a welder or has used one knows wtf. I will agree I have seen some crappy "certified" welders. One of the best welders I had in apprenticeship was really good although not much of a teacher.
I have worked with guys that had some experience with little formal training, my claim to fame in that dept is getting to the root of what they don't know and are doing wrong, I have had a lot of comments like,,, wish someone had shown me that 20 yrs ago. Lots of practice isn't worth a **** if its done wrong. I can usually spot guys with good training vs the learned it by practice method. Many learned well from others on the job. I ran across one a while back, 30 yrs, never did learn it right, would have thought in that time he would have asked someone that did,,, but no, they assume because they been doing it they been doing it right. Lots of mechanics and trades people in that boat.
Seen a young guy with very little experience that knew exactly what he was doing too, someone clued him in right off the bat.