try lightly tapping the joint with a lighter,that has always worked for me. also if you keep your joint connections dry then they wont get stuck anymore.
I just use my creme brulee torch from bed bath and beyond to head the outside joint up for around 10 seconds on med-high. then tap inner joint with a wooden spoon with a slight upward motion, careful not to hit the joint so hard as to send it airborne. let the glass cool down 3 minutes before touching it with anything, don't want to crack anything or cool glass down faster than normal. its worth the wait.
