I suspect straight urethane is better than putting epoxy under it. That way you don't have to worry about the epoxy suddenly turning white! Although the urethane will last longer than anything else, it'll be a bear to strip if you let it go too long, so if you go that route, it would pay to maintain it well!

Here we go!
 

I have removed a few pieces of teak. It was very coarse. sanded with 150, then 220. Pleased with everything except the wood putty that was supposed to be stainable. I wish I had found this site before I went to repairing/ patching the teak.

Looking good and nice varnish choice:D