I am also trying to dismantle an OLD semi trailer, probably from the 1960s. For two days we used a sawzall with 14tpi blades, and got very little done. Someone recommended an angle grinder but said the blades would be ate up fast. someone recommended a torch. someone recommended a bandsaw. I have found that aluminum with a sawzall is very difficult because of the constant vibrating. this trailer is 75 percent aluminum... the sides, the floor, with only steel beams underneath and steal hinges on the doors. the sawzall goes through the steel like a hot knife through butter. what is best for aluminum? a torch? a grinder with cutoff blades? what brand do you recommend for this job? dewalt? skil? hitachi? etc? I need something heavy duty. the owner of the trailer is willing to pay up to 2000 dollars to have it cut up and hauled off to a scrap yard. dont know why, but he is. so please help us figure something out.