<HTML><HTML>List Recently bought three bottles of CA from Schaff, one of each viscosity.&nbsp= ; All three were kept together, first arriving in a plastic bag, and then e= ntering my "glue kit".  I opened the thin bottle and when examining ea= ch of them today that one is still good.  Much to my amazement, the me= dium viscosity, which had never been opened, is solid as a rock.  I th= rew it out.  How could that happen?  Still sealed in its bottle, it somehow hardene= d into a solid mass.  Meanwhile, the bottle which had been opened, and= the remaining closed bottle are both still good. What the hey? Tom Sivak Chicago</HTML>