I use the vulcanizing patch system. In my cycling class in college they taught us how to properly repair a tube in the seventies and these type patches were fairly new out. The only problem with the system is that you have to check your tube of glue regularly to make sure it is not dried up. I mentioned this to my LBS when I was buying new tubes of glue . The mechanic told me that when I finished with the repair to carefully fill the cap with glue before putting it back on the tube of cement, thus creating a "seal" . I haven't had a flat since I replaced all the glue in my seat packs so I have no idea if it works but I will try next time I am in that situation(flat tire). I also keep a spare tube with me. Joe joesvintageroadbikes.wordpress