Originally Posted by
noglider
When the patch is dry, the edges should not show any gaps. At that point, it is tempting to add glue to finish the job. This is guaranteed not to work. Peel the patch, clean the tube, and start again with a new patch.
I've occasionally had issues with edges not sticking, and added a bit of glue, and the patch did seem to hold.
However, it may be that it still was good over the area that was patched.