2. An air-powered reciprocating saw will help you cut large areas fast, but remember it doesn't make for a clean cut. It leaves edges that are jagged and it tends to distort the metal if the blade locks up in the middle of a cut. To prevent that from happening, make sure you lube the blade with cutting fluid. This type of saw also rattles the material, so get a good grip on it or anchor it down with a clamp.