SWMBO came out to the garage one day to ask a question, and before she walked out, I went back to the air chisel. She screamed at me that it was loud! Well, of course it was, but I had earmuffs on and couldn't hear much at all...I forgot other folks didn't have them.
pretty much what midlife said. i used it to take apart all of my spotwelds. only time you have to drill is if you want to save both pieces that are spotwelded. the air chissel will for sure destroy one of the two pieces. you can choose which one it is.
It will usually tear a little chunk out of the piece you're removing, but you can go back from the other direction and peel off most of it. You'll end up with bumps where the welds used to be no matter what.
I plan on going back with a grinder to smooth the flanges a little. The new repro piece already fits in pretty nicely; once I grind out what look to be some old repair welds, it should be 100% in place and ready for welding in.
Darn that it's the only piece of sheetmetal I need to rip out!