Dudley,

Since you already have the stabs mounted you might want to consider simply stripping the covering from the undersides of the stabs to access the internal structure.

As I stated a few posts back, I opened my stabs to install hard balsa blaocks for the Robart Hinge Points that I chose to use over the stock CA hinges. That is when I discovered just how thin the trailing edges of the stabs and leading edges of the elevators were. The material is most likely metric, but it appears to be about 3/16" thick which I don't believe is enough material for these types of hinges. I decided to use 3 Hinge Points per elevator, one about 1.5" from the tip of the stab and the other two on 3-3/4" centers. This put each Hinge Point between the existing ribs of the stab.

My suggestion would be to cut the elevator hinges and switch to the small Robart Hinge Points. You could use standard hinges but due the lack of material in the stab trailing edge and elevator leading edge, you'd have to add internal blocks to allow pinning the hinges. IMO, it would be easier to utilize the Robart Hinges. Once you determine where you want to locate the hinges you can just open the skins on the bottom side of the stab. I cut openings of about 3/4" width by 1" long, centered on the pilot holes drilled for the hinge points. Then cut custom balsa blocks and cemented them into position. Before I glued the blocks into the wing, I carefully dripped CA onto the intersection of each rib and the upper/lower wing skins tilting the parts as needed to allow the CA to run along the rib/skin interface. I also cut openings to allow direct access to the CF tubes to insure they are glued securely to the ribs. Once satisfied with everything, all I have left to do is close the underside of the stabs, fill the cracks, and recover the bottoms of the stabs and elevators.

HTH

Rich