I used this to repair some polyethylene tanks (gas and water) and, with practice, it works well. No adhesive will really glue polyethylene so it must be welded. I have previously tried using a blow torch, a soldering iron, or even a heated nail to weld such tanks, but it’s never been good. It does take some practice to use this hot-air “welding torch”, but once you get the hang of it, it’s good.You can buy packs of plastic welding rods, or use scraps of the same kind of plastic. If the tank tries to collapse inward, rig up a way you can blow air into it with your mouth or an air hose to keep it inflated. This particular model has the blower unit separate from the heater/torch unit, which I think is a good idea. The ones that combine the two are cheaper, but the blower is rather bulky and not very convenient to hold. I think this 2-part model is better.