I don't know if I would use it to splice 2 sawed tubes, but for a cracked or bent part, then I could trust it 100%.
Lately I have been making things with CF and epoxy. My first practice test was to wrap a broken steel fork with 2 or 3 layers.
2 days later I lay it on the cement floor and hit it as hard as I could with a hammer. The epoxy surface dented some. I kind of doubt a car jack could crush it now.