A clear polyurethane product, when applied to wood, can form a good bond, and will seal the wood adequately. The seal coat prevents off-gassing and the formation of bubbles when you apply TotalBoat TableTop Epoxy over the polyurethane seal coat.
However, for a much stronger bond, use a thin coat of epoxy instead of clear polyurethane, to seal bare wood before applying TotalBoat TableTop Epoxy. The epoxy will take longer to cure, but it will create a much stronger bond.
If you do decide to use a clear polyurethane product, we strongly advise that you do a small test sample to make sure you get the desired result.