I've got an abandoned 275 gal home heating oil tank that's left in my basement from when I converted to natural gas. The plumber who did the conversion said that I could cut the top half of the tank off with a sawsall in order to get the thing out of the basement (won't go out in one piece). I tipped the tank up at about 45 degree angle and managed to drain everything from the tank. I was planning to vent the tank to the outside and dump 5 pounds or so of dry ice into the thing before starting my cut to drive out the oxygen. Anybody have any thoughts on this? Would prefer not to blow myself and the house up in the process..