Abstract: A sheet metal assembly includes sheet metal pieces joined by a weld joint. An initial weld joint is subsequently conditioned in a manner that reduces the size of a recess in the initial weld joint and/or changes its grain structure. A laser beam or other heat source can be used to condition the weld joint. The resulting change in weld joint geometry and/or grain structure improves the formability of the sheet metal assembly at the weld joint and is particularly advantageous when butt welding same-gauge sheet metal and/or aluminum alloys.