I made a dining room table. Grain filled and finished with Arm-R-Seal oil based urethane. 24 hours in the clamps and 72 hours to cure. Used biscuits for alignment so wanted to make sure all the glue had time to cure that would be deep in there. The grain filling took some time, so that would be more time for glue to cure. Table sat for 3 weeks before I put it into use, somewhere in that time the tiniest of bumps came up along the glue lines. Not everywhere but enough to notice when you rub your hand over what was a glass smooth table. They are not visible unless you catch the light just right. They are not bad, a quick sanding and I imagine they would be taken care of. Any idea what caused this to happen and how to prevent it in the future?