I bought some epoxy at least two years ago. Possibly 3 years. For the last 6 months or so I've had knife handles come apart. These have all been back lock folders with one-piece handles. The handles have replaced the existing FRN handles. FRN Dragonfly2 is one of the knives that have had 2 or 3 handles come apart on one side or the other of the backspacer. I just finished fixing the handle but this time I used 3 3/32" pins through the scales and backspacer. I called USAKnivemakers and asked them if epoxy has a shelf life. They said yes, if not used within 2 or 3 years it may not hold as well as when used when it wasn't as old. I was surprised to hear that. But, I don't remember if I have glued handles together that have pressure applied "sideways" on the joining surface like the single piece FRN handles. The back lock spring appies constant pressure on the backspacer. I don't know if this makes holding the pieces together harder or now. Anyway, my question is has anyone else heard or experienced unused epoxy (resin and hardener) loosing it's adhesive capability over time? If not, I might assume my use of the glue may be improper. I've been using epoxy since I was around 10 years old and never had this issue before. I use coarser (220 grit or lower) sandpaper to roughen the areas making contact and make sure they are clean. Any help is appreciated.