How many seal coats do I need, and do I sand between them?

It depends on how porous the surface is. A standard wood surface only needs one seal coat of UltraClear Bar & Table Top Epoxy. Older, rough, or reclaimed wood, raw burl veneer, and very porous materials like corks can need 2 to 3 seal coats. If your first seal coat soaked in and left dry-looking patches, the wood is absorbing it: brush on a second or third seal coat before the flood coat. Keep each coat thin and even. If there are vinyl decals on the surface, seal them with Mod Podge first.

Space the coats 4 to 6 hours apart. Recoat within 10 hours and no sanding or prep is needed; the layers bond as one. Past 10 hours, lightly scuff with 220 or 320 grit sandpaper, then wipe with a clean lint-free rag and denatured alcohol or acetone (never paint thinner or mineral spirits) until all dust is gone. The same window applies when pouring UltraClear Deep Pour Epoxy over seal-coated river edges: one seal coat is usually enough under colored Deep Pour; under clear Deep Pour, you can do multiple seal coats so trapped air can't escape.

A seal coat that looks rough, uneven, or shows brush strokes is normal; the flood coat smooths it out. But if the epoxy is separating or fish-eyeing instead of soaking in, something on the surface (oil residue from a tack cloth, for example) is preventing adhesion and must be fixed before any more epoxy goes on.