100% all plastics are certainly not equal - a very generic term. I used to use Z-Poxy from 5 min to 30 min, depending on where on the rods I was using it. With a 'through' action rod, you still get some flex right down to the reel seat and I never had a failure but that's not to say that 'some' types of plastic might behave differently.Maybe not all plastics are equal?
When using epoxy for wooden boat building I used to use blue plastic dpc membrane to mask areas that I didn't want stuck, because the epoxy wouldn't adhere to the plastic. I think that's normal practice when using epoxy resins.
Also, I once tried to patch a hole in a plastic dinghy using epoxy. The patch just fell off.
