Oak veneer is in most homes in some capacity. If you have a desk, cabinets, chairs, end tables, paneling or any other type of home decorating that includes hardwood woodworking, chances are you have oak veneer somewhere in your home. Oak veneer is a thin sheet of real oak glued to particleboard, plywood or any other composite to make it appear as if it were solid lumber. It's not uncommon for veneer to crack, bubble or separate over time if it's exposed to sunlight or water. It also can fail because it wasn't properly attached when it was manufactured.
Insert the tip of a utility knife into bubbled oak veneer. If you have access to the side of the bubble, insert the tip of the knife there, under the bubble. If the bubble is somewhere in the middle of the veneer, make a small slit in the bubble with the knife.
Inject glue under the veneer through the hole or slit, using the tip of a glue bottle. Insert the knife back into the hole and spread the glue as far as you can with the tip of the knife. If the bubble is more than 2 inches long, make another slit and inject more glue there. If the separation is wider than 2 inches, use a putty knife to spread the glue.
Replace any broken pieces of veneer. If a piece breaks off, place it back on just as it came off. It might appear as if were a piece of a puzzle. Move it around until it fits perfectly. Press it down with your fingers until it sticks in the glue.
Place a piece of plastic wrap over the area that you glued. Put a small block over the area — it should be big enough to cover the bubble — and place a clamp on the block. Clamp it tightly to flatten the bubble into the glue. If you can't get a clamp on it, place as many heavy objects on the block as you can find. Books work well. Let the glue dry for at least one hour.
Remove the books and plastic wrap. Scrape off any residual dried glue from the area, using the putty knife. You may have slight cracks in the veneer. Use a color-matched putty crayon to lightly putty the area. Wipe it clean with a dry cloth.