Can I buff or polish scratches out of epoxy instead of recoating?

It is possible, but it is not what we recommend.

Some customers with polishing experience have removed scratches and restored a high-gloss finish with 3M Finesse-it II, a high-gloss polishing compound. Technique is critical: too high a speed smears or softens the epoxy, and too low a speed leaves it cloudy. Always test on a small, inconspicuous area first. Polishing epoxy is done at your own risk, and getting a result that looks like freshly cured epoxy is extremely difficult even with skill.

The fix we recommend is to scuff-sand the surface with 220-320 grit sandpaper, clean off the dust with denatured alcohol or acetone, and pour a new flood coat of UltraClear Bar & Table Top Epoxy. The new coat cures to a high-gloss, glass-like finish on its own, with no buffing, and the surface looks brand new again. That applies to touch marks on Deep Pour Epoxy too; the repair coat is still Bar & Table Top Epoxy.

A note on early scratches: the epoxy keeps hardening toward its 98 Shore D rating for weeks to months after the pour, depending on the environment. It is fine to use after the 3-day cure, but use placemats and coasters in the early stages to avoid marks.