Brazing is still a common repair, but for a lot of repairs we use TIG over gas torches. For cast iron, I do a variety of repairs. TIG brazing with silicon bronze and aluminum bronze is my go-to. It usually doesn’t require much pre-heat and it works great. Another repair I’ll use a lot is 309 stainless with a significant preheat (300-400F) and I’ll slow the cooling rate. 309 is a very ductile alloy and will allow the casting to move as it cools. Of course, there are Hastelloy and other fillers specifically for welding cast iron, but they are incredibly expensive and it’s less worthwhile to keep around whereas it seems like ER309L will weld almost anything with iron in it.When did brazing go out of style? For many things it's still a very viable process I would think, especially with cast iron and thin wall tubing.
For thin tubing (<.100”), TIG welding, especially with a remote amperage control, is much faster and leaves a better finished product with better properties.
I'd like to know that also. It was a very satisfying type of welding to do many years ago for me.
I’m not exactly sure when, but I would say whenever TIG became a refined enough process to be faster and more effective than gas torches.