Kitchen Floor Finish

Three coats of polyurethane, and I gots me some floor shine....

The title of this post is not completely true because I still need to add epoxy to the larger gaps and knot hole openings to avoid a food catch-all. I tried Clear Coat epoxy but it was so viscous that it just disappeared into the sub floor. I need to either find an epoxy thickener or a pre-caulk method to contain the epoxy. Suggestions anyone?