Combine 3 cups premixed shellac and 2 cups denatured alcohol in a small basin with a paint stirrer. Dip a 3-inch paintbrush in the mixture and wipe down the blotchy pine with this washcoat. This will create a decent foundation for you to start over on.
Attach a piece of 320-grit sandpaper to the bottom of an electric sander. Run the sander across the surface area of the furniture. Wipe it down with a soft cloth to remove resulting dust.
Dip a foam brush into a jar of a deep brown or burnt umber-shaded glaze. Apply a light coat of the glaze to the pine. Allow it to penetrate the wood for 5 minutes and then wipe off the excess with a lint-free cloth. This will even out the color of the wood. Evaluate the wood color and add more glaze, if you like.
Dip a 3-inch paintbrush into a can of tinted polyurethane. The color of the polyurethane should echo the color of the glaze. Cover the pine in a light coat of tinted polyurethane and allow it to dry for 24 hours.