Takes a long time to dry. Let's see if it holds up to the weather. I glued flat balloons onto a styrofoam balloon to make my own observation balloon. I was only able to glue a few rows a day for a few weeks as the long drying time of the glue on a round surface caused them to shift. Also, I had to use a lot of glue or my marble wouldn't stay in place. So the ball isn't ready yet, but the tube of glue is over. But the glass seems to be sticking pretty well.