Originally Posted by
vtjim
Epic saga! My patch did not fail. There was another hole, suspiciously close to the hole I patched. Very suspicious. The LBS couldn't find anything in the tire, and neither could I, so they replaced the tube...
Hard to do this on the road, especially when dark/cold/wet, but an easy trick for detecting insidious bits of glass remaining inside the tire is to drag a cotton ball through the entire inside circumference. The cotton should snag on any offending bits left behind.