We learned to bend pipe/tubing by hand with a torch and filling it with sand while in HT "A" school many years ago. I have the exact method in a book somewhere, but the short version is this: fill pipe/tube with sand and make sure it is tightly filled. Cap or plug both ends. Now lay out your bend using a MBR (minimum bend radius) of 4 times the radius. The bend can be made to a tighter radius, depending on ID, wall thickness, material etc... but is usually done with a machine. Graduate the length of your bend into 3/4 or 1 inch increments. You will need a length of tight fitting pipe to go over the tube to use as a cheater. Heat the first graduated area all the way around and then apply cheater pipe and bend. How many graduations and how many degrees to bend each one will have to be determined by the fabricator. An easy example would be a 90 degree bend over 9 inches is nine 1 inch graduations each bent 10 degrees. The results were pretty dang good, but it is time consuming. If you are into fabrication and metal work, give it a shot. There are some other alternatives that may suit your needs better though. I have never tried bending a sand filled pipe/tube in a bender. If you try this, let us know how it worked.