I think there is enough - none of my Robarts has ever come loose. One tip - after drilling the hole (I actually use a small screwdriver - more accurate for me) - I use a pushrod to get the 30 min epoxy into the hole before inserting the hinge. Then, when all the hinges are glued and inserted, stand the wing up with the leading edge pointing up, so that the glue that's still liquid might slide down the hinge and form a plug against the wall. And, of course, use vasoline or oil on the hinge pivot itself, to keep the glue out.