It really wasn't just the issue of using CA hinges per se. The hinges supplied were bad material and about 6 of mine had delaminated and fell apart before I ever got a chance to put them in. If that had happened after installation, I'd have had a serious problem.

Also, like you said, the slotting is the key. When I stripped the covering, I found EVERY hinge slot (precut) was doublecut. There were two slots about 1/16" above/below each other at every point. These slots were all crooked as well, causing them to meet at one end, forming a "V" wedge between them. This wedge had broken loose on most of them and slivers of balsa were just falling out of the surfaces.

Also, the LE and TE of the surfaces wasn't exceptionally thick, with slivers of balsa falling out of the backside into the wing, which left you very little surface area for the CA hinge to glue to and a very poor glue joint. I just did not feel safe with these things after seeing what I really had. Everything looked fine with the covering on... had I not stripped the plane, I would never have known what I was in for... just like the crushed ribs.

Tom