How do I repair bubbled or lifted veneer? This depends on the type of glue that was used to glue the veneer down and if the bubble or blister formed after the finish was applied.
My veneer was glued with PVA (white or yellow) glue or hide glue, how do I fix the bubble? This is probably the easiest problem to fix. Applying heat to the affected area will reactivate the glue. Using an iron (yes, an iron that you use for clothing), you should be able to heat the area so that the veneer sticks to the substrate again. Do not put the iron directly on the workpiece, always put a sheet of paper towel or thin rag between the iron and the workpiece so that the iron does not burn the veneer.
The glue used cannot be reactivated by heating or I do not know what type of glue was used to glue the veneer, what can I do? A possible solution would be to take a small craft knife or utility knife and make an incision along the grain in the center of the bubble or blistered veneer. Gently slide or inject PVA glue in the lifted area underneath the veneer. Then apply pressure to the area by clamping a block of wood to the area for about 30 minutes, or until you are satisfied that the glue you have used is adequately dry.
I cut the bubble, inserted glue, and glued it down, but now there is a small overlap bump because the edges of the veneer don’t match anymore? This happens because the veneer has slightly expanded. You will have to very slightly sand the veneer overhang until it is flat again.
The bubbles only showed up after I applied the finish, what happened? It is possible that you used a finishing product that has the same activating agent as the glue. In this case the finish that you put on your veneer soaked through the veneer and made the glue unstick. Depending on how much bubbling there is, the piece may not be able to be repaired. Otherwise you can try one of the above methods above to repair you veneering work.