There's a great video on repairing a severely damaged tuba, which includes the use of the magnet-ball for straightening the walls of the tubes, as well as disas

There's a great video on repairing a severely damaged tuba, which includes the use of the magnet-ball for straightening the walls of the tubes, as well as disassembling parts of the tuba to gain access to individual parts: https://www.youtube.com/watch?v=wflildRmcJw https://www.youtube.com/watch?v=wflildRmcJw