Simply use a piece of old inner tube about six inches long. Pierce the tube tube an inch or so in from either end, and push it onto the barrel of the torch through one end, pass the tube through a vent and out the other side, and push the end of the torchinto the second hole. Use another piece of tube betwen the torch and the helmet to stop it scratching the finish. It's cheap, adjustable, and i'm sure you could make it look tidier if you are self-conscious!