My JB Weld + fabric lasted 2/3 of my 5 mile bike trip today. And POP! Yup ... it blew at the tear, right thru the PATCH! When I examined, I noted no JB Weld in the tear, and also, the inside fabric had shifted away from the hole -- so it was as if I done NOTHING but patch the innertube. I also inflated the tire to my normal practice (85 psi, the max for the tire). So that may have been part of the issue.
On closer inspection, I noted that the rear tire (which was never rotated with from) is considerably more worn than the front (sidewall cracks, etc.). OTOH, plenty of tread on both tires, as well as those mold-release spikes.
I want to play this experiment out as far as it'll go! Hey, tires and tubes are a "dime a dozen". Experimental data is worth billions of $!
So here's the game plan:
I rotated tire/tube (all OEM) front << -- >> rear.
To the tear, I added 3 layers of Gorilla tape (duct tape) on the inside of the tire. I also added some Gorilla tape on the outside of the tire. It looks a bit ghetto, but the tape is black, so not too shabby!
I'm still going to use 85 psi. At that pressure, I note very slight bulge at the tear. Let's see how long this lasts.