I need to cut a couple of 10-inch diameter semi-circles out of some galvanized, corrugated steel roofing. I use tin snips to make straight cuts, which works OK. But you can forget about doing anything remotely fancy with those things. At least I can. For long cuts, I use a metal-cutting blade in a Skill saw, after donning the safety glasses and earmuffs. Tools I have at my disposal include: Sawzall; Dremmel; Table Saw; Hand-held circular saw; Drill None seems terribly promising. In my experience, tin work just plain sucks. Any suggestions?