ORIGINAL: da Rock
Never pinned hinges other than the one time some years back.
Never had any surface pull out. Never had any hinge pull out. Had a number of stab flutters and not one hinge failed even when there was damage back there. Those most certainly would be significant tests for hinges pulling out.
If you install any hinge into a tight slot with the appropriate amount and type of glue, nothing more is needed.
BTW, I've used nylon hinges for quite awhile, since they came out. Started using CA hinges when they showed up because they were so simple and quick. But they looked risky so I tested with a number of glues. If they're installed correctly they're bulletproof. The only ones I've ever experienced that failed were in a really cheap model and they looked cheap. I've yet to see any that looked cheap since.
If you don't do the pinning job correctly, there is a strong argument that you're actually weakening the hinge area.
Of course, most "craftsmen" whose skills lead them to pin, would also be ones who are apt to pin improperly. It's a never ending circle, ain't it.
I kinda disagree with daRock.
Never had any hinges pull out either, but I alway pin them, both nylon and ca hinges.
In your other statement, if installed correctly, they are bullet proof??? , complete nonsense, Nothing in this hobby is bullet proof!
Your third statement, about weakening the hinge area is a gray area, . The pin's, if installed correctlyare away from the hinge line, not right next to it. The failure in the hinge area itself is caused by applying to much ca glue, then it saturated the hinge area, then it becomes brittle, then it breaks.......The pin's will help, to prevent the other hinges from giving way, or braking if you did not saturate the other hinge's the same way.
I have seena few planes, lawn dart at our field, reason,......... ca hinge failure. I have no idea howthey were installed, but the one's I did see, the hinge pulled out completly of one section or another or both on different occasions,Wings ripped off,with the wood.With different pilots on different days.. When I saw this, and I am not an expert,by any means............. but when I use Ca hinges, I always pin them anyway.I just like to have, in my mind that hinge is not comming out period.
The ONLY hinges I do not pin are Robarts, CAUSE it's more difficult., If you use em, you get the drift..........