Place the reclaimed door on a work surface. Use a screwdriver to remove any hardware that is on the door. Set the hardware aside. Brush the entire surface of the door with a wire brush to remove any debris or loose finish.
Place the reclaimed barrels upright on a work surface, side-by-side in a row. Draw a 16-inch diameter circle in the center of one side of each barrel using a compass. This will be the opening for the bar storage space inside the barrels.
Drill a hole through the barrels inside the circle using a drill equipped with a 1/2-inch drill bit.
Insert the blade of the jigsaw through the holes and saw along the circular line made by the compass to cut out the 16-inch diameter circles from the barrels. Remove the circular cut outs from the barrel and set them aside.
Sand around the circular openings in the barrels with a fine-grit sanding pad until the openings are smooth.
Lay the reclaimed door across the top ends of the barrels. Center the door over the barrels. This is the bar top. Hammer square head nails through the door into the barrels. Evenly space four nails per barrel top to secure the door to the barrels.
Brush on two even coats of shellac over the exterior of the barrels, around the edges of the circular openings and over the entire surface of the reclaimed door using a natural bristle paintbrush. Allow the shellac to dry 24 hours between coats.
Insert one stemware rack through the opening in each barrel. Center the racks on the inside, tops of the barrels. Drive the screws that were included with the racks through the mounting holes into the barrel with a screw gun. Store your stemware on the racks. Store your drink bottles and other supplies on the bottom of the barrel.