Brazing is another technique for fusing metal together, often to achieve a water tight or air tight seal.  Normally brazing is done in a furnace or with a large burner.  The laser can be used for repairing existing brazing by using a large de-focused spot size.  This is a heat source which is used to heat up a local area to achieve the melting point of the braze material.  Laser brazing is in its infancy and so there  are few brazing materials in a suitable wire size, but small areas can be brazed or re-brazed with silver solder onto steels or nickel alloys and aluminium braze onto aluminium alloys.

The radiator leaked (pictured right) and was repaired by laser brazing.