Stephen at work, brazing

Brazing is perhaps the oldest technique for joining metals other than mechanical fastening, and its historical development parallels the development of materials. Earliest evidence indicates that mixtures of metal salts and organic reducing agents were used as filler metals to braze gold and silver base metals.

                      
                              Torch technique is key  
  
                  The ancient at the top of the page depicts a man engaged in gold brazing with a charcoal fire in a clay bowl, a reed for a blowpipe, and tongs to hold the work. Later advances led to the use of copper and brass alloys as braze filler metals. As the development of the base materials progressed from the noble metals, to stronger copper and iron-based alloys, to the present range of metallic alloys, parallel developments in the sophistication of braze filler metals and techniques have occurred.

                  
                      Tandem bottom bracket detail

Brazed and polished seat tube cluster