monokote hinges
I used to be a fan of monokote hinges. I've done several models with one piece of covering going all the way from Leading Edge, through the hinge gap, then back to trailing edge of control surface. I would leave a gap such that I would get monokote on top stuck to monokote on the bottom for at least 1/32" or 1/16" along the full length of the hinge, believing that the two would never come apart. And so far that's how it has turned out.
The problem is with my latest instance of this technique, in which I used an old roll of monokote. I find after about thirty flights the hinge gap in my ailerons is coming apart, the monokote cracking right down the hinge line. So far only a couple inches, but I don't like the way this is going.
The tail is hinged with ultracote, of more recent vintage, and that is holding up very well. I notice the old monokote is a bit more brittle. When I start a cut in it, it slices very easily with a sharp blade. The ultracote, on the other hand, seems tougher and more fibrous; when I cut it with a sharp blade, I get a more ragged cut, as though I were cutting across a grain of some kind.
One more thing: I had a deadstick landing in which the plane came down off the edge of the field, where the ground slopes down. I was able to see and control the plane all except for the last few feet, when it went out of sight. The plane landed maybe a bit hard, but still on its feet with no damage, except for one bay of the stick-built ailerons, where the monokote split across the one bay, diagonally across opposite corners. There was nothing the aileron could have hit, since the inboard end was protected by the fuselage and the outboard end was protected by a further 3" of fixed wingtip. I expected the monokote to be tougher than that.
So I am still sold on the idea of film hinges, but I think I will use ultracote from now on instead of monokote for this purpose.