ORIGINAL: sclitheroe
OK, so it is because of the pulling forces, for horns...Not all hinges are internal though - I'm not using CA hinges on this model, but rather the regular external ones that you glue and pin. No bolts on those either, correct?
-Scott
I detect a potential gross conceptual error here. You're referring to "external" hinges. The hinges DO NOT lay on the outside of the control surface. Rather, you cut a slot on the mid-line of the control surface, put the glue on the hinge, and insert the hinges into the slot.
After the hinge glue has set, many people will drill a small hole down through the hinge in the control surface, and insert a wooden toothpick down through the hole. This "pins" the hinge in place.
Brad