hi sages- have repaired at least 50 flat tires since 69 when I started using radial tires(used bias ply tires 65-69). always have done it the same way and never had a problem: take wheel off car, inflate tire , locate puncture by hearing the hissing or use soapy water on suspected spot. remove cause(nail, spike, bullet, screw, shrapnel, etc. deflate tire, clean hole with tire reamer, put rubber cement on reamer and run through hole, put plug and cement on slotted end of insertion tool , push into and twist plug into hole and once through pull back out so part is outside tire and other part is inside tire. by plug I mean these black sticky strings that look like pipe cleaners from the parts stores. then let the tire sit for a few minutes and inflate. can even check repair with soapy water for leak bubbles. have never had a problem with these plugs leaking, failing or coming out. tire stores tell me what I do is no good and I should bring the tire into them, pay them $25-35 to dismount the tire,put in a plug, trim it and glue a round patch to the inside of the tire, of course rebalance and restem the remounted tire and road test the car(where they will surely discover the need for new ball joints,pistons and muffler bearings). don't think this is necessary and is just another ripoff for those clip joints who need to make a home run. don't mind a single or even a double but still hate home runs. what think you(maybe I have a bad attitude). btw I do this for tread punctures. if the puncture is on the edge of the tire or the sidewall, its usually curtains for the tire. btw #2 have heard that it is not legal to repair tires this way. think that is a canard. thanks tons oldduke