Has any one had any luck welding a cast iron exhaust manifold? I have a crack near the drivers side rear bolt on the exhaust manifold on my 69 340 Dart. It leaks (ticks) for a couple of minutes after startup until it warms up, expands,and seal the leak. I practiced welding a cast iron brake rotor with .030 flux core MIG, and it held up pretty well, but after some hits with a hammer, the weld broke. It was obvious that the weld doesn't penetrate the cast iron. Any ideas on a better way to weld this?