Brazer

A brazer is a tradesperson who performs brazing, a metal-joining process in which a filler metal is melted and drawn into a joint by capillary action. The filler metal typically has a melting point above 450°C, while the base metals are not melted. Brazing can join dissimilar metals and complex shapes, and it is distinct from soldering (lower temperatures) and welding (fusion of the base metals).

The brazing process involves several steps: preparing and cleaning the joint to remove oxides, applying flux to prevent oxidation, assembling the parts with an appropriate joint gap, heating the assembly evenly, and introducing the filler metal so it flows into the joint by capillary action. Heating methods include torch brazing for localized joints, furnace brazing for controlled, repeatable joints, and induction brazing for rapid, efficient heating. Brazers select filler alloys based on the metals being joined, desired strength, and corrosion resistance; common families include silver-based alloys, copper-phosphorus, and aluminum-silicon for aluminum work. Fluxes, such as borax-based compounds, are used to protect the metal surface and promote wetting, with residues later cleaned to prevent corrosion.

Applications of brazing span plumbing and HVAC (joining copper pipes and components), automotive and aerospace (heat exchangers, airframes, and critical joints), jewelry making, and electronics cooling assemblies. In many industries brazing allows joints with good strength and thermal conductivity without subjecting base materials to high temperatures.

Safety and quality control are important in brazing. Work requires proper ventilation to manage fumes, protection against heat and flame, and careful joint design and cleanliness to ensure reliable, leak-free connections. Brazing differs from welding in that the base metals remain unmelted, and from soldering by using higher temperatures and stronger, more load-bearing joints.