I have steam heat with cast iron radiators. One of the radiators has developed a leak, either a pinhole or small crack. The leak is on the inside of the fin of one of the sections, so it is not easily accessed. Does anyone have any ideas on how to stop the leak? Alternatively, can I take apart the radiator and remove the leaking section? The house and radiator are about 75 years old, and Im afraid that taking apart the radiator will just create more leaks. Thanks for your help.Eric