PE-HD (high-density polyethylene) welding rod is the correct filler for HDPE pipe, large water and chemical tanks, geomembrane and landfill-liner work. HDPE must be welded with a genuine PEHD rod — a PEMD or PP rod will not fuse properly and the joint will fail under load.Techspan PEHD rod is produced from virgin material for consistent melt and high weld strength, making it suited to tank fabrication, pipe repair and civil/geomembrane applications. Available in 3 mm, 4 mm and 5 mm round profiles plus triangular and rectangular profiles, in 50 m and 400 m rolls. For thicker HDPE sections an extrusion welder is usually the better tool. Not sure of the grade? Our plastics identification guide will help you confirm it.