I always have a few half-used tubes of caulk and glue lying around. Usually by the time I get around to using them again, they’re hard as a rock. I had tried just about everything when, during a recent bathroom remodel, I had both the caulk gun and glue gun at the ready. On a whim, I capped the partially used caulk tube with a dab of hot glue from the gun. I’ve used that caulk twice more over the past few months, replacing the hot-glue cap each time, and it’s as fresh as the day I opened it.
Glenn Ravdin, South Hero, VT