Ever have to bend an odd sized piece of tubing (like a transmission dipstick tube) without kinking it?

Close off 1 end (tape will work if it’s far enough away from the heat) and fill the tube with fine sand. Then heat the tube and put your bends in. The sand keeps the tube from collapsing or kinking. Pour out the sand, rinse out the tube with brake cleaner and compressed air and you’re done.