Pedestal tables typically rely on a single, vertical post for support. Bases should be substantial, but not imposing. They need a certain amount of ballast to keep the top-heavy table from tipping. If you have a traditional pedestal table that's missing a base, or the base has deteriorated beyond repair, build a stylish pyramid-style base to support almost any pedestal tabletop using a few pieces of medium-density-fibercore plywood. MDF is a composite product that looks like hardwood. It's heavy enough to provide the weight needed to support your pedestal table.
Place the 3/4-by-18-by-18-inch piece of oak MDF on a flat surface. Apply wood glue to the face.
Place the 3/4-by-17-by-17-inch piece of MDF on top of the 18-inch piece and square the edges. Shoot 1 1/4-inch pin nails randomly through the 17-inch piece to bond it to the 18-inch piece.
Apply glue to the 17-inch piece of MDF. Place the 3/4-by-16-by-16-inch piece of MDF on top of the 17-inch piece. Shoot pin nails randomly through it to bond it to the 17-inch piece to form the pyramid base.
Sand the base by hand using 100-grit sandpaper. Round and smooth all the edges. Blunt all the corners. Apply stain and lacquer, paint or varnish as needed. Allow the base to dry overnight.
Turn the pedestal table upside down. Remove any screws, nails, brackets, chunks of wood or debris from the bottom. Sand the bottom of the post lightly using 100-grit sandpaper. Place the pyramid base on the post, center and square it. The 18-inch piece should be facing up. Trace the outline of the base from underneath. Remove the base.
Drill four holes, evenly spaced, 3/8-inch from the inside edge of the perimeter of the outline, using a drill/driver and 5/16-inch drill bit. Countersink the holes to a depth of 1/2-inch using a 1/2-inch drill bit.
Place the base back on the post of the upside-down pedestal table, using the outline to align it. Drill through the holes using the 5/16-inch bit just enough to create a small divot for each hole on the bottom of the table. Remove the base from the post of the table.
Drill four pilot holes in the base centered on the divots to a depth of 2 inches using a 3/16-inch drill bit. Apply glue to the bottom of the post. Place the base back on the table post, aligning the holes in the base with the pilot holes in the post.
Place 1/4-by-3 1/2-inch lag bolts into the holes. Use a 3/8-inch socket and ratchet to drive the bolts into the bottom of the post, securing the base to the table.