If you mean tightening them up, I suggest using liquid floor polish (like Pledge or Future). I use a toothpick to put the liquid into the joints and let it set for a few hours before re-applying again if it's still too loose. As for cracked elbows: I don't think there's a cure for that.

Byron Kellogg ..i would suggest to use loctite or superglue to drop a little amount on the elbow joint and just blow it off a bit and keep the joint movin until the glue dries up and it gives really nice perfect tight tension to it