How long after setting objects in the seal coat can I pour the flood coat?

Wait 24 hours. When you press buttons, shark's teeth, coins or other small items into a tacky seal coat of UltraClear Bar & Table Top Epoxy and let it act as the glue, the seal coat needs a full 24 hours to harden and take a firm hold before the flood coat goes on. That is past the normal recoat window, so before you pour, lightly scuff the cured seal coat with 220-320 grit sandpaper and wipe off the dust with a clean rag and denatured alcohol or acetone. The flood coat fills the sanding scratches and cures clear. Waiting longer than 24 hours is fine; just do the same scuff and clean first.

The other option is to glue the items down before sealing. Any adhesive works except hot glue. Once the glue has set, apply the seal coat over the surface and the items as normal and carry on with the flood coat per the instructions.

Hollow-backed objects such as buttons do not need to be filled. Either method seals the air pockets behind them so they cannot release trapped air into the flood coat. If you are not sure an item is fully sealed, apply a second seal coat over it before the flood coat to be safe. If you have never worked with epoxy, test the process on a small piece first.

Bar & Table Top Epoxy instructions: https://cdn.shopify.com/s/files/1/0320/7168/0140/files/Epoxy-Instructions.pdf?v=1616443869