One of my steam radiators has a small leak under the bottom. No hole is visible, but water drips out at a rate of a few drops per minute. Various websites suggest applying a 1 mm thick layer of J-B Weld after sanding and cleaning with acetone.
Does the fact that the radiator leaks necessarily mean that it is completely rusted from the inside and that leaks will soon appear elsewhere? Or is it likely that a slow leak is not due to rust, or that the rust is in only one place?
The radiator is decades old (perhaps even a century), but has been moved recently in order to repair the floor. The leak is clearly away from the valve.