As per an earlier thread, I ended up epoxy coating one decayed wooden
gutter (with multiple coats and some fiberglass) and one undecayed
wooden gutter that I just surface coated with the intention of
preventing future rot.

Now since epoxy is UV sensitive, I assume I need to coat the epoxy
with something to protect it from UV.

What would be the best coating that would stand up to the water-logged
nature of gutters and to sun UV exposure? I am looking for a solution
that requires the least maintenance and repeat coating.

Would you recommend paint? If so what type and is primer required?
What about a poly spar varnish?
Any other suggestions?

Note: after applying the epoxy coating, I noticed someone cautioning
against epoxy (or any other non-breathable) coating of wooden gutters
since trapped moisture can rot the gutter from within if the coating
is impervious. The site recommends instead breathable coatings like
various oils. But I went with the advice on this group (and also the
advice from West Systems tech support) and it's too late...