Q: We wanted the strongest joint possible so we used epoxy, but the joints are failing. Any comments?

A: Epoxy often does give the strongest joint, but there are a few key items that must be considered.

  • First, epoxy requires a thick joint. If you use normal pressure, you likely will make the joint too thin and this means weakness. Consider, if edge gluing, making the surfaces to be glued slightly rough or make them hollow ground (face to face).
  • Second, epoxy must be combined in the proper ratio (resin and hardener) and then must be mixed properly (per manufacturer's instructions).
  • Third, even the fast curing epoxy requires at least 24 hours to develop its full strength.

Of course, all the standard guidelines apply. It's particularly important to note that the adhesive must be clamped promptly before any curing occurs.

Also, epoxy does well on oily wood, but even these woods should have the surfaces cleaned just before adhesive application.

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