Get thin CA.

Medium CA will depsit solids in the hinge line, leading to premature hinge failure. The medium will also fail to "wick" into the hinge slot, giving a poor bond at best... and often will not penetrate more than 1/8 inch. (just enough to feel like the hinge is secure, and then let go shortly into the first flight)

The thinner the CA used with the hinges, the better. I've gotten better results with CHEAP stuff that doesn't seem to hold other things well, than with Zap or Jet brand. (which are great for any other place you'd want to use CA...) The cheap stuff soaks in better, and the chemical treatment of the CA hinge material delays the, already somewhat slow, cheap CA's setting, for deeper penetration and a better bond.