Thank you for the follow ups and the tip on the Zinsser product. I found a Q and A on the net that explains why the shellac needs to be dewaxed:
Is there any difference in the sealing properties of Zinsser’s SealCoat (dewaxed shellac) and regular Bulls Eye shellac? I have had trouble finding SealCoat. Can I use regular shellac as a sealer instead?
Both of these products seal the wood equally well, but some finishes won’t stick to regular shellac. Both amber and clear Bulls Eye shellac have a natural waxy substance that interferes with the adhesion of oil-based polyurethane and water-based finishes. To address that problem, Zinsser created SealCoat, a dewaxed shellac, meaning it has the wax removed. That’s why you see SealCoat advertised as a “Universal Sanding Sealer” on the can.