Can't help with the epoxy question but I used Beckson hatches on my latest wood strip greenland kayak and am very pleased. I used the screw in instead of the pry out kind. After hearing where someone blew out one of the pry out hatches in surf, I like the security of the screw in hatch.

Keep in mind as someone else said that they must be mounted on a flat surface. I created recesses to mount mine in. I've included a link to show what the hatches look like mounted. There is a 6 inch in the front and an 8 inch in the back deck.

Don't plan on camping out of the the kayak unless you have some ultralight/ultrasmall gear, especially if you have a low volume boat!