I just went back and re read your post. I see that you have stick built your wing (again) I have to wonder what caused the failure of the first one/s? Did you use spruce for the top and bottom main spars or did you use balsa? How many bays did you shear web? Did you use balsa or spruce for the sub spars? The Sig flat bottom Kadet wing series uses two main spar and two sub spar construction techniques. On the main spars, I normally select spruce for the spars, and 3/32 balsa for the shear webbing. I normally run the shear web the full apan (plans call for about 5 or 6 bays) (if I remember correctly) I have tried adding shear web to the sub spars, but I didn't feel that I gained enough strength to overcome the weight added.

I fly the Senorita pretty aggressively, and have never had a failure with the airframe. This model is over 10 years old and has over 500 flights to date. It flies in local fun flys, and is always a force to recon with. The wing is still rubber banded on, and the only mod to the fuselage is that the perimeter frame is 1/4 spruce instead of balsa. Did the same thing with a Sr. Kadet once, and it flew well with a Saito .91 The flight envelope was awesome to behold. (wings bolted on (not completely stupid)) It was sold several years ago, and as far as I know is still flying.

If you did not shear web the mains, I think that it would be worth removing the covering (from the bottom) and adding the shear webs.

Bill