Plastic repair GURUS since 1981
Nitrogen Plastic Welding:
Standard Operating Procedure
This SOP will walk you through the steps of a basic nitrogen plastic weld.
IMPORTANT: Before you begin any repair process, please remember your personal protection. Select protective eyewear, respirator, gloves, clothing, and hearing protection appropriate to the job and level of exposure.
Find the ID symbol molded into the part and select the matching welding rod. PP (polypropylene, aka TPO or TEO) is the most common type, but PE (polyethylene) and PC (polycarbonate) are also quite common.
Work out any distortions with heat and pressure. Clean plastic, then grind a v-groove into the backside to match the width of the selected welding rod. Use aluminum tape on the frontside to hold damage in alignment as you weld on the backside.
Use the nitrogen plastic welder to weld the filler rod to the base material. Direct welder’s heat to melt both plastics at the same time, applying slight downward pressure on the rod to fuse them together.
When backside weld cools, peel aluminum tape from the front. V-groove at least halfway into the plastic with a die grinder, about the same width as the selected welding rod.
Again use the nitrogen plastic welder to melt the base material and the welding rod together, applying a slight downward pressure on the rod. Apply multiple passes of rod if needed to fill v-groove completely.
When weld is completely cool, sand with 80 grit in a DA sander to profile. Apply a skim coat of two-part filler as needed to finish the repair and prepare for primer.