First Method: Heat and Pressure

For hollow-sounding blisters, try this simple approach:

1. Using an old iron, apply it directly to the surface of the blister. Place a barrier, like greaseproof paper, between the iron and the veneer to prevent scorching.
2. As the heat flattens the blister, quickly press a flat, heavy, cold metal weight onto the area. This helps the glue beneath re-cure as it cools.
3. Keep moving the weight to absorb residual heat while holding the veneer flat.

This method works because older furniture typically used water-based animal glue, which softens when heated and re-bonds when cooled.

Second Method: Injecting Glue

If heating doesn't work, or for stubborn blisters, try this:

1. Carefully use a scalpel or craft knife to lift or create a small slit in the blister.
2. Apply glue into the cavity using a cocktail stick or another improvised tool, ensuring minimal further damage.
3. If the veneer has swollen and can't lay flat, you may need to trim a tiny amount from the edges before gluing it down.

Third Method: Substrate Repair

For severe blisters caused by swelling of the substrate beneath the veneer:

1. Carefully cut away the blistered veneer but don't discard the pieces—you may be able to reuse them.
2. Using a sharp chisel, remove the swollen substrate, taking care not to dig too deep. If necessary, fill the void with wood filler to level the surface.
3. Reattach the original veneer pieces if possible. They may need slight shaping to fit, but they'll match better than new veneer.

If reusing the veneer isn't feasible, replace it with a new piece that closely matches the original in color and grain. To disguise the repair:

• Cut the replacement veneer into an oval shape, slightly larger than the repair area.
• Trace around the patch and cut away the damaged area to create a snug fit for the new piece.
• Patience and precision are key here.