Will a welded muffler cause rusting?
As has been pointed out, there is welding somewhere along the way on all mufflers. Even the ones that are pressed together have their inlet and outlet pipes welded in place, probably because it’s cheaper than trying to extrude all that stuff and you still need to weld in the baffles inside the muffler. Is your question that you are considering welding a muffler into place rather than using clamps to hold it in place? The fact is that some small exhaust systems are one solid welded piece. The more bends and turns a system has to make the more likely it will be in multiple pieces. In addition single systems usually just have small parts of them rust out so they are then replaced by after market parts that are clamped on. The cause of rusting is moisture. Mufflers do a good job of trapping moisture, especially on very short drives where they don’t have a chance to heat up enought to burn up the condensation created at start up. I have many cars that don’t get driven a great deal. I dril a
