How much do I sand cured Deep Pour before the Bar & Table Top coat?

Only a light scuff. Once the UltraClear Deep Pour Epoxy has cured for at least 3 days, lightly sand-scuff the whole surface evenly with 220-320 grit sandpaper. Light is enough; you do not need to sand heavily. But do not skip it: this step is what ensures the UltraClear Bar & Table Top Epoxy adheres to the cured Deep Pour.

Then wipe all the sanding dust off with a clean, lint-free rag and denatured alcohol or acetone, and let the surface dry completely.

The scratches will not show in the finished piece. The flood coat fills in the sanding scratches and cures with a clear, glass-like finish again, as long as you follow the mixing instructions. Properly prepared this way, the new coat bonds fully to the cured epoxy with no delamination.

Use the same prep for a Deep Pour surface that has been sitting uncoated for weeks, and for cured epoxy from another brand. Whenever cured epoxy is being re-coated, the routine is the same: let it fully cure, scuff with 220-320 grit, clean, dry, pour.

Once the Deep Pour is clean and dry, seal coat any remaining exposed wood, wait 4-6 hours, then pour a 1/8" flood coat of Bar & Table Top Epoxy directly over it.