Posted for Gary Casey <glcasey@adelphia.net>:

 Don't take my word for it, but I've used out-of-date materials and  the
advice I got from a real expert was that if it goes to a full  cure then it is
okay.  I store all of my epoxy in a refrigerator, but  didn't start doing it
until a lot of it had gone past its expiration  date and so far I can't tell
any difference.  That experience matches  what we have found at work.
 
 Gary Casey