Can UHMW be welded?

Yes, UHMW can be welded. Virgin UHMW is preferable, but factory-regrind is also weldable. Some UHMW with silicone and other additives is not weldable. Also, some colors cannot be welded because of the types of pigments and dyes used. The only way to know if it can be welded is to try it.

Recommended Tools The welder that we recommend for welding UHMW is the 2001 FC Seelye welder, part number 42463. The welding rod that you should use is 3/16” HDPE part number 46030. You will also need to purchase a 3/16” welding tip part number 42021.

Requirements for Air Supply and Electrical Source You must have a clean, dry air supply with a minimum of 50 PSI and 5 CFM. You can use compressed air to weld UHMW, but this does produce smoke, and ventilation is required. Nitrogen can also be used, and it will not produce smoke. Both air and nitrogen will produce the same quality weld. You will need a 20 AMP circuit, 120 volts.

General UHMW Welding Instructions Start the welder by plugging it into the air and electrical supply. Activate the pressure switch by turning the air pressure between 8 – 10 psi. Then turn the pressure down to 5-1/2 PSI on the gauge. The welder will take about 7 minutes to heat up completely. The parts to be welded must be beveled or have a fillet. Hold the 42463 with the 42021 tips at almost a 90 ° angle to the surface to be welded. Doing this allows you to apply as much hot air to the substrate. Feed the 3/16” HDPE welding rod at 12” per minute through the tip barrel. At this low rate, the welding rod turns clear, except for a thin white line in the center of the rod. You will observe some puddling of the substrate. Do not move welded part until the welded area is back to the original color and firmness.