IF he's as bad as you say, then he's probably peeing the pax off as well... And ATC... And the engineers... And, and...
In your shoes (and presuming that you are effectively running the operation, as I imagine you are), then it's time for a written warning, and then the sack if he doesn't shape up fast.
Uncomfortable atmospheres on the flight deck mean trouble, and in the environment you're in, you need all the cards stacked in your favour.
If it was me? I'd probably just get rid. There's no shortage of good right-seaters at the moment...