Arc weld
Veteran Member
Brazing wouldn't take much heat...and it's possible with simple Oxy/acetylene. You don't have to heat the metal up to melting point. It is slower, but reliable for patching and some joining repairs. I never worry about cracking with this process since the bronze/brass is softer and can "stretch" as it cools. I supposed you could use MIG brazing (Si/Bronze) as well and do it a lot quicker.
Brazing cast iron usually requires just about as much preheat as O/A welding it but is easier because you don't have to melt the base metal.