I used Ca hinges in my 1/3 Scale Great Planes ARF Pitts and had the same problem. May of the hinges split. I replaced them all with CA hinges again but this time I stuck a pin in the center and slid the surfaces together with the pin in place. This left a small gap so the hinge would not crack with surface moved. No problem since. I was trying too hard to seal the gap. A pin sized gap should be no problem. I now love CA hinges.

KEEP FLYING!!