Brazing is often the tidier process, but not on load paths, hot sections or parts that must be inspected. The tests a joint has to pass before it is chosen.
Copper and brass pull heat away from the joint faster than stainless, and the two expand differently. Handling the mismatch, the flux and the galvanic risk.
Brazing spreads heat over a region instead of a point, so the part moves less. Where the advantage is real, where it vanishes, and how to measure the result.
Aluminium gives little warning before it collapses and its oxide blocks every filler. Working inside the narrow window without melting the sheet underneath.
Flux breaks the oxide that stops filler wetting, then stays on the part. Where the residue hides, what it attacks months later, and how to remove it properly.
Brazing a patch onto a welded part mixes two processes in one place. What that does to the original heat-affected zone, and when the section should be cut out.
A silver-bearing filler lets a small fitting be joined to light tube without collapsing it. Cleaning, heat control and feeding the gap, plus when to weld instead.
A brazed joint is a designed clearance. Too tight starves the filler, too wide defeats capillary action, and both faults can look acceptable from the outside.
