You can add rigidity to a sheet-metal box or bucket by folding the top rim around a thick wire. This detail gives a professional finish to shop-made Sheet Metal Parts projects.
Bending the Wire to Fit the Rim
Measure and cut a length of wire equal to twice the combined length and width of the box, plus twice the diameter of the wire. Clamp the wire in a vise with about 1-1?2 inches extending from one side. Hammer that short section to a Right-angled bend, then unclamp the wire and pass through the vise an additional length equal to one side of the box. Reclamp for a second right-angled bend. Unclamp the wire, and repeat the process twice more. On the fourth side, Don't butt the wire ends together at the corner, but rather, about 1-1?2 inches away from the corner bend. This will strengthen the corner seams of the box and give the appearance of continuous wiring all around the rim.
Fixing the Wire to the Rim
Slip the formed wire into the folds that you have left partially open around the top of the box. Fit the box over an improvised support or the flat end of a mandrel stake. Use pliers with taped jaws to press the wire snugly into the fold at Work with the side in small sections, moving the pliers as you go so that you are always holding the wire close to the sheet metal being flattened. All the way around the rim, rotating the box on the support as you work.
Setting the Edge
Upend the box on the work surface and crimp the edge farther around the wire by tapping along it with the square face of a setting hammer. To complete the tucking, reverse the hammer and drive the metal edge behind the wire with the hammer's tapered peen.