On the back, just above the UPC code
Is the " Use By Date " Mine expires 01/23/2011 Lot no#601232
Does this stuff go bad. YES IT DOES. I work at Brown Machine. We make Tooling for various things. One part is called a Plug Assists. This part pushes the plastic into the die, to form a cup... Ok, Big deal. The Foam we use, gets glued to Aluminum, with Devcon Plastic Putty. I had close to 90 parts lose. I found this out as I was turning the contour, on a couple. Imagine my surprise.