less if you have the sandpaper lying around!
my suggestion would be to pick up 5$ worth of 400 grit norton wetsand (5 sheets). unless the coating is super thick even the 400 grit should make short work of the rubberized stuff, and the finish will be a nice medium between 200 (you'll see scratching) and 600 ("fine grit" for most purposes, although i typically like to go up to 2000+ grit for a serious polished finish)