Mahogany veneer is typically no thicker than about 1/16 inch. It's bonded to a substrate of plywood or lesser-quality wood with glue under pressure. When used on furniture, tables or even doors it remains stable for years. However, if the veneer is exposed to direct sunlight or moisture the glue can fail. Other problems can occur during manufacturing, causing bubbles or separation of the veneer from the core. This type of separation usually causes a bubble or buckle in the veneer. You can repair it with ordinary wood glue.
Cut a very shallow 2-inch slit in the top of the buckle using the tip of a craft knife. If the buckle is longer than 6 inches, cut two slits evenly spaced 2 inches apart.
Pry the slits open using the tip of a putty knife, and inject wood glue into the slit. Insert the tip of the putty knife under the buckled area. Work the glue under the loose veneer as far back as possible on all sides using the putty knife. Add more glue if necessary.
Place strips of masking tape on both sides of the slits. Cover the buckled area with clear plastic, and then flatten the spot down with a block of wood. The wood block should be bigger than the buckled area by at least 1 inch on all sides.
Apply clamps to the wood block if possible. If the area is not accessible with clamps, place heavy objects on the block such as boxes of hardware, books or anything needed to compress the buckle flush to the surface. Allow the glue to dry overnight.
Remove the clamps or heavy objects, the plastic and tape. Apply mahogany wood putty to any cracks or slits that are visible if the veneer has not been previously finished. When the putty is dry, sand the veneer parallel with the grain using a hand block with 150-grit sandpaper. Sand carefully! Veneer is very thin, and you don't want to accidentally sand all the way through. If the veneer has been finished, use a putty crayon to fill any cracks, splits or slits. Wipe the veneer down with lemon oil to finish.