How to adapt top radiator threads to steam air vent

Bob W._3

Steve, my take on this is that a vent near the top will shut too fast, if the radiator has a top manifold, as the steam will go up and across the top. The regular vent should be about 2/3 of the way up, and the 2nd vent would be below that, about 1/2 way up from the illustrations I've seen. I would drill and tap.

Steve Garson_2

How to adapt top radiator threads to steam air vent

I want to try the approach of using two air vents on a thin tube radiator. There happens to be a threaded hole and plug near to top of the radiator that would normally be used for a vent if the radiator was used for hot water.

Assuming I could get this plug out, what kind of adapter would I need to fit a steam air vent to that hole? Or is this not a good idea? I'm a bit skittish to drill a hole in cast iron and then tapping it.

Timco

I mig welded a nut from the threads to the plug...this heats the plug and gives you a nut to turn to apply force and break it free. Worked all 4 times I did it.

T