I happened to be playing with one when this article popped up in my RSS feed. It's my sons but it's on my desk because I tried repairing the cracked frame with super glue, for about the 5th time. It still works with the cracked frame and the repair didn't take this time because I mindlessly starting playing with it while the glue was still drying. We've had 3 around our house for about 2 weeks and everyone that lives or visits, in age groups from 60's down to 10 months have fidgeted with them almost every time they come across one.
Cyanoacrylate can't handle nonporous materials - as you're seeing, it dries so brittle that an incautious glance will snap it.
Try epoxy instead; it's slower to cure and smells funny, but produces a much stronger bond, and doesn't have the same problems bearing mechanical loads. I like J-B Weld and J-B Kwik, which are strong and resilient as hell (you can fix tractor engines with them!) and double as a low-temperature casting material for additive repairs, but for what you're dealing with here, the cheap Loctite stuff on the drugstore blister card should do you.
With metal or almost any plastic, you can do what you like to the surface, and cyanoacrylate still won't hold all that well - if you (correctly) use a very thin layer, it'll last longer, but that's not the same thing as really being reliable. Quicker and easier just to epoxy it once and be done.
