Re: Bedding Deck Hardware With Butyl Tape
Sometime you have to make compromises and butyl alones should do the trick. Potting with epoxy is great practice but it's a second line of defense that should hopefully never be needed if the primary seal is good. The vast majority of all the holes in boat decks are not potted with epoxy and many do just fine after many years.
If you do think about epoxy I'd consider overdrilling instead of the more time consuming practice of gouging out core through a smaller hole. It sounds like it's a lot of holes but the advantage there is the economy of scale. You might be able to move pretty quickly depending.
The last line of defence against water intrusion is to try to make sure water has a way to get out if it gets in. NEVER seal from the inside. Wood on the outside of the boat lasts for decades after all because although it does get wet it also quickly gets dry.