You're talking about a liquid modeling cement like Testors, Djmodels?
It's nice to know I'm not the only one that has trouble with super glue drying up in the tube. (I always have a spare new tube handy for just such an emergency.)
While we're on the subject, how do you keep excess super glue from oozing out of the tube after you squeeze out just the right amount onto your dispenser? In my experience, thick-gel super glue is especially prone to continuing to pour out of the tube after I squeezed out all I need. The last time I used thick-gel super glue, all I needed was a drop or two for a liftgate hinge. I squeezed gently, but the tube continued to POUR glue all over the place, and all I could think of to do (tapping the tube, holding the tube upright, blowing down into the opening) didn't work. I was even frantically hollering at the glue, "STOP ALREADY!" (This was akin to yelling at the TV when your favorite football team screws up, and it worked about as well.) Needless to say, the glue wouldn't stop coming until about half of it was wasted. Question: How do you make it stop before I have to relegate half the stuff to the trash?