Abstract: An extrusion is provided which includes an upper double sidewall and a lower bulbous portion forming an integral pallet structure. This extrusion can be cut to suitable lengths and welded at the corners to form a sealed rectangular container bottom. A bottom panel is welded around its peripheral edge to the extrusion lengths. Reinforcing I-beams can be placed across the bottom and laterally spaced openings can be cut in the ends and sides of the bottom portions for receiving fork-lift tines. These cut-out portions can be reinforced by tubes or channel members, as required. This structure minimizes the critical welding required to make a sealed container bottom, since only the corner welds and the bottom panel welds are located where air leakage can occur.