The BAK 20mm wide slot nozzle (BAK article 5107123) push-fits onto the ø32mm outlet of a hot air hand welder. The 20mm x 2mm outlet lays a narrow band of hot air along the weld line, so you keep control on flashings, corners, small overlaps and repairs on TPO and PVC membranes, tarpaulins and thermoplastic sheet.
Fits these welding guns
- BAK RiOn Hot Air Welding Gun 230V
- BAK RiOn Digital Heat Gun 230V
- Leister Triac AT Heat Gun
- Leister Triac ST Heat Gun
The 32 mm push-fit outlet is the common size on trade hot air hand welders, and other brands use it too. Check the outlet on your gun if it is not one of the models above.
Where the 20mm works
- Flashings, corners, parapets and penetrations where a wider outlet overhangs the weld line.
- Small overlap seams, patch edges and repair work.
- Tarpaulins, liners and thermoplastic sheet.
Welding technique: heat the overlap with the nozzle, then press the softened seam with a silicone pressure roller as it cools.
20mm or 40mm?
The BAK Wide Slot Nozzle 40mm (article 5107132) is the standard roofing seam width and the nozzle size BAK ships with RiOn welder kits. Choose the 20mm for detail work and narrow weld lines. Roofs with field seams plus flashings usually carry both.
Good to know
- Nozzle only. A hot air hand welder is required and is sold separately.
- For hot air welding of thermoplastics. It does not suit propane torch-on bitumen work.
- BAK makes angled-base and bent variants under different article numbers. Match the article number 5107123 to your gun manual when you order.
- Weld inside the membrane manufacturer's temperature window and test a weld before production work.