2.2 lbs/cu ft (35.2 kg/cu m) closed-cell polyethylene (PE) foam Natural color (off-white) Water absorption: Less than 0.3 lbs/sq ft exposed (1.5 kg/sq m) Less than 3% by volume Per ASTM D3575-Suffix V, EN 28301, ISO 2581 tests Buoyancy: 58 lbs/cu ft (930 kg/cu m) Completed foam sections heat-welded (not glued) and hot-wire shaped to finished profile