Applying paste wood filler on any open grain wood, especially red oak, will eliminate the waviness over the surface of the board. Paste wood filler should be applied by a wide blade putty knife and worked into the open grain of the wood. This process is followed removing the excess and finish sanding with an orbital sander with 220 grit paper.
This is followed by application of a sanding sealer. The paste wood filler fills the open grains in the wood, due to machining and the sanding sealer neutralizes the "raising the grain" process, by securing the loose elements of the open grain cells of the wood. After drying, sand the wood with an orbital sander with 400 grit paper. Change the paper frequently, to avoid gumming up the paper.
When introducing the finish, that is high in moisture content, the grain does not raise, thus a flat surface, for applying the final finish coats. This is what I learned from working with finish guys at the furniture shop. Their table tops were smooth as glass, even in the right light.
I hope this information is helpful.
Tony
