Hot gas extrusion welding

When welding plastic with a hot gas extruder, the welding rod is melted inside the device and pressed into the prepared groove with a stream of hot air. The groove must be clean and dry, otherwise the seam won't hold. You have to set the temperature so that the rod melts cleanly without burning or dripping. Guide the device evenly and with constant pressure, then you'll get a tight, load-bearing seam. If the seam becomes porous or bubbly, it's usually humidity or temperature that's the problem.