By saying blowtorch I actually mean a gasoline blowtorch. Don't now what it is? Well, it's a steel tank with a handle, an air pump and a burning assembly on top. The burning assembly consists of a pre-heating tube, a vent and a nozzle. If you don't have this thing, you can use your propane torch but with care because it's a lot hotter than the gasoline one, and you can just unweld the muffler seams, so don't open it to full throttle.