With the inner panel completely cut out, we turned our attention to rolling the edge. Since this panel is large, we welded in a brace to help keep its shape. We want to be sure to maintain 90-degree angles between the floor, side, and top of the well. Although it's not necessary, I usually shrink the edges of a piece before running it through the tank-roll dies. The dies stretch the sheetmetal and warp the metal slightly, so in theory, this helps prevent some of that warpage by pre-shrinking the sheetmetal.