I hereby admit that I am incapabale of patching a tube so it wont leak. I think I am doing it right -- scuff surface, apply vulcanizing fluid, let dry, apply patch. the patches always look nice. But every time, the tube leaks. Not a lot. The tires hold air well enough to ride to work and home again at end of day without need to reinflate. But instead of losing a few pounds of air over 24 hrs, the tire with patched tube will lose maybe 20 or 30 lbs and invariably dunking inflated patch in water reveals oh so slight bubbling somewhere around edge of patch. Since I reinflate every ride, anyway, perhaps this isnt a big deal, but its irritating nontheless. Welcome any advice for patching tubes so they dont leak.