Short answer: yes. Pour the next coat while the first is in its "green" stage (firm but slightly tacky, often 4–12 h for coating resin) for a chemical bond. If it has fully cured, sand it evenly with 220–320 grit, wipe with isopropyl alcohol, and pour; the new coat bonds mechanically.
Same as the first: area × ⅛" ÷ 1.805 = fl oz. A 24×48 top needs about 80 fl oz. Use the tabletop calculator or the layer planner.
Yes. Sand it with 220–320 grit, clean off dust with isopropyl alcohol, then pour.
Not if the first coat is still in the tacky green stage. After full cure, always sand.
Pouring on a dusty or unsanded surface, or a big temperature difference between coats. Sand evenly and keep the room warm.
More tools: resin calculator · tabletop coating · river table · deep pour · cure time · pour layers
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