Sometimes you simply don’t have a good sharpening stone or other knife sharpener handy. Well, there’s a simple trick that can quickly hone a dull edge in just a couple minutes and this object, a car window, can be found nearly everywhere.

This works really well on a knife that doesn’t have major damage to the edge but just needs a little touch up. If you have large nicks or gouges in your blade you’ll need to use other methods.