A method for joining weldable metal structures and compound structure formed using the method are disclosed herein. The method includes steps of abutting a first structure to a second structure along an edge to form a seam. The two structures are then welded together along the seam on one side of the structures through at least 75% of the thickness of the structures. The structures are then welded along a portion of the seam from the opposite side of the structures. The method may be used to join porous weldable metal structures. The method may be used to create a compound structure having very narrow weld seam widths.