How to Reglue a Countertop
Q: "How do you handle a large bubble in the middle of a countertop?"
Is there a way to re-stick a countertop's laminate?
— James Monroe, Vinita, Okla.
Tom Silvia replies: The loose edges were probably caused by moisure seeping into the joint over time and causing the particleboard, which is underneath most countertop laminates, to swell and flake. So try this: Lift up an edge slighly and swab some polyurethane glue in there. A large paper clip or a finishing nail makes a good glue spreader. Be careful, though; the laminate will crack if you lift it too far. Push the seam down and immediately use a rag moistened with mineral spirits to wipe off any glue that squeezes out. Then put a piece of waxed paper over the area and weight or clamp the edge until the adhesive cures overnight.
The bubbled areas in the center of the countertop were probably caused by heat from, say, a hot pan that melted the adhesive. The solution, odd as it sounds, is to heat the adhesive again, then press the bubble back in place. You can use a hair dryer, a heat gun, or a clothes iron with a lightweight towel to raise the temperature to 140 or 150 degrees. Again, you need to be careful; too much heat can char the laminate. While the laminate and the glue are hot, immediately push the bubbled area down with a rolling pin and weight it heavily for 24 hours.
If that doesn't work, I'm afraid you'll have to live with it or replace the countertops.