Hey homebrewers - I have a small air compressor with a rather small tank (1.5 gal), but it mostly fits my needs for light duty. Though, every now and then I encounter a slightly more demanding job and wish I had a larger tank so that the compressor isn't cutting in so often. Given that I often have an empty corny keg I begin to wonder if its safe to pump it up to ~120psi to use as a portable tank? The compressor's manual states that the air from the compressor "is not safe for breathing", but I'm thinking it would be fine in the keg. A dedicated portable tank is fairly inexpensive, but it takes up valuable space.
And yes, I realize that I really shouldn't have an empty keg sitting around, but that's life.