I know there are a lot of uses for old/worn out/too many holes inner tubes but the other day I was out of patches and so I thought about it and determined to give it a shot. I cut out a piece of "old" inner tube, cleaned it along with the spot where there was a hole with rubbing alcohol then buttered (put rubber cement) on both pieces. The place where the hole was in the inner tube and the cut piece of inner tube. So far so good. No problems for over two weeks now, so it doesn't look like I'll be buying any "patches" in the near future.