The corner of my countertop is expanding. How can I fix this? I thought about removing some of the excess particle board, fill with Liquid Nail and then press close.

Any ideas?

 

I assume you are referring to the laminate endcap on the end of the counter. Sometimes these do come unglued. You can reapply with laminate adhesive.

If the particleboard has swollen due to moisture, you need to address the moisture issue. If the moisture issue has been addressed, and swollen particleboard has dried out, then perhaps you can 'shave' off excess particleboard and reapply endcap with laminate adhesive. If particleboard has swollen outward and popped endcap loose, chances are it has also swollen in thickness and you will not get a proper fit when you reapply endcap.