I am however a fan of brass fillet brazing, which BTW takes place in the range of about 1400 degrees-ish whereas a brass brazed lugged joint is in the 1750 degree range. Silver brazing takes place around 1150 degrees. I've had the same opinion for over 30 years and I haven't seen nor heard any valid reasons for that to change.
My question: Why do you say that brass fillet is at ~1400F and brass lug work at ~ 1750F? Is it that you use a different rod, that the lug requires higher temp to get the the whole assembly hot enough to flow whereas fillet has direct flame exposure on the tubes, or something else?
Thanks John Clay Tallahassee, FL