Yes, seal the wood before you pour, especially if the wood is porous, such as plywood, oak or such, and most especially the edges of plywood. Then you can do a deep pour.
I prefer to use a deep pour epoxy. It is thin and fills in all the small places. It is slow to set and I let it set overnight, maybe even 2 days depending on the weather. That gives it time for any bubbles to float to the surface and resolve themselves.
I do not use a heat gun to speed the curing as that might cause bubbles and, at the same time, speed the curing to the point that the bubbles do not have time to float to the surface and resolve.
Hope this helps. Don't give up just because you had a bad result on the first try.