I always have a tube of silicon cauking laying around. I'm usually not in a hurry so I clean the tube, scuff it up a bit with a piece of sandpaper, apply the silicon about 1/8 inch thick, swirl it around good with my finger, and let it dry overnight. I have never had one to leak. I even put a new & costly set of tires on my Cadillac Seville. About 2200 miles later I ran over something and punctured 1 tire with a hole that was too large for a plug to hold. I wasn't about to throw away a new tire so cleaned, scuffed, and applied the silicon about 3/8 " thick on the inside of the tire, let it dry overnight and threw the tir away about 27,000 miles later. Call me a redneck, I don't care.