Can I use epoxy to make, coat, or repair a cutting board?

No. No epoxy, ours included, should be used on an actual cutting board, whether you want to coat the whole board, cover a knot, or fill cracks and voids in it. This is standard across all epoxy finishes.

It isn't a food-safety issue. UltraClear epoxy is 100% VOC-free and cures into an inert, non-porous plastic, so incidental food contact is not a problem; it's used on restaurant bars, tabletops and countertops for that reason. The problem is the knife. Cured UltraClear Bar & Table Top Epoxy is a commercial-grade finish that is extremely durable and scratch resistant, but epoxy surfaces are not intended for direct cutting or food prep. Keep a standard cutting board for cutting and food preparation; that protects both the food and the epoxy finish.

What you can do is make a charcuterie board or serving tray. UltraClear epoxy has been used on those for years without issue. Use UltraClear Bar & Table Top Epoxy as the finish coat, and fill any void, knot or crack 1/4" or deeper with UltraClear Deep Pour Epoxy first, then top coat it with Bar & Table Top Epoxy. Both products can be colored with Pigmently mica powders or liquid dyes; test the color on a small scale first, and see the pigment FAQ: https://ultraclear.helpscoutdocs.com/article/80-epoxy-color-pigments