Yes, great advice. No one is laughing. It takes experience to gain experience.
I'm a very competent sheetmetal whacker/welder. Last month I have been helping my dad on a rusted door. We fought contamination and blowouts. I had it all TIG welded, and planished out, looking good. Shined a flashlight through the back and found LOTS of places I missed the line, or didn't penetrate enough and ground off the bead...
When it comes to sheet metal, there are 4
simple rules. You can
cut it,
weld it,
shrink it, or
stretch it. That's it.
I cringe when I hear the word: WARP. There is no such thing. In the process of cutting, and welding, you upset the metal. It is going to happen. When you are done, you need to stretch and/or shrink places to get it back into shape. Cutting stretches, and all welds shrink! Learning to deal with this = experience.
Flame suit on...