Get some Duncan bisque mender...great stuff. You dampen and scratch
the clay where you need to reattach something, put some bisque mender
(generous amount) in the scored area, score it a bit more, and press the
two pieces together. The stuff has saved many a break in my class.
Also, another reason you don't fire bisque and glazes together:
Cone 04 is bisque temperature. You bisque to this temperature so that
your clay will be as hard as you want it to be before you glaze. Your
glaze temps for 05 or 06 are lower than 04 bisque. Reds and other
colors that are fired to 04 don't come out right. When you only bisque
to 05-06, you run the risk of leaving your clay body not fully fired for
maximum durability and strength. Also, some glazes won't "fit" right on
a skimpy bisque, and you are inviting glaze flaws, especially with
underglazes. Hope this makes sense.