Dave,
CA glue works but not as good as ABS cement. It appeared that
previous owner(s) had used CA glue to patch some ABS plastic cracks in
our plane. In some areas, the old CA glue cracked (probably due to
thermal expansion mismatch with ABS which eventually caused fatigue
cracking). Patching ABS plastic with ABS material eliminates this
problem. Areas with thick globs of CA glue did not crack but turned
brownish yellow and looked pretty ugly. If only a small amount is
needed, one can make ABS cement by dissolving small ABS shavings in
MEK. For bigger repair job, the premade ABS cement can is the way to
go.