Re: epoxy barrier coat sun exposure how long is too long?
If you have more than just a few hull blisters (behind the barrier coat) you may have a damp hull. If this is the case you really need to strip the barrier coat now as well so the hull can breath for a year and dry out. If it is just a few isolated spots then that isn't necessary.
If it is just a couple, I would tarp the hull once the paint is gone. Putting latex paint over epoxy may be fine, I have never done it, but a $5 blue tarp from Wal Mart will do just as good a job at keeping the epoxy in good shape, and be a whole lot easier to remove.