Al Smith
Mac Daddy
As far as cast iron you have several options .Pre heat/post heat or no heat with stitch welds and peening .The later has worked the best for me over the years .To me Ni rod works the best although it's very costly to use .Depending some stainless rod could work like 304 or it might not .There is also the use of gas with cast iron filler rod and borax flux but it's almost an art form to it .I can but I'm not an expert but my Dad RIP was . For a lot of thing brazing works well .