Do I need to sand between epoxy coats, and what grit should I use?

It depends on how long the previous coat has been curing.

If you pour the next coat of UltraClear Bar & Table Top Epoxy within 4 to 6 hours of the previous one (10 hours at the most), no surface prep is needed. The layers bond together as one. This applies to the seal coat before the flood coat, to a second flood coat, and to thin layered coats where you paint details between layers.

Past 10 hours, once the epoxy has cured hard to the touch, scuff it first:

1. Lightly sand-scuff the entire surface with 220 or 320 grit sandpaper. 2. Wipe off all the sanding dust with a clean, lint-free rag and denatured alcohol or acetone. Do not use paint thinner (mineral spirits). Keep wiping until the surface is completely clean, then let it dry. 3. Pour the next coat directly over it.

Don't worry about the sanding scratches or the cloudy look they leave. The new coat fills in the scratches and cures with a clear, glass-like finish again, as long as you follow the mixing instructions.

Bar & Table Top Epoxy is hard enough to sand about 12 hours after pouring, so you don't have to wait for a full cure before recoating. The same scuff-and-clean process works on a surface that was epoxied months or years ago, such as an old countertop. Use the coverage calculator at https://www.bestbartopepoxy.com/pages/epoxy-calculator to work out how much epoxy the new flood coat needs.