So I'm looking to make some approx. 45* bends in some 3" exhaust pipe. I've read about how you can cap off one end of a straight piece of pipe, pour the pipe almost full of sand, and then pack in a tight wad of newspaper in the other end (with help from a hammer to get the sand packed in tight) to hold it in. Then you just take an oxy/acetelyne torch, heat up where you want to make the outside of the bend, and push the pipe as you heat it. When there's enough heat, it will stretch and make a nice smooth bend. The sand keeps it from collapsing like crush-bent pipe. Soooo, with the price of mandrel bends and the effort to cut and weld the bends in place, it seems like sand bending at home would be a good way to go. Anyone done it? Is it very difficult to get right?