After years of sailing as crew I bought my first boat this year and am facing, for the first time, many of the maintance issues which more experienced boat owners have mastered. This week's problem is a leak that has developed around a chain plate. I think the previous owner encountered this based on the copious smearing of some kind of gray gunk around the chain plate covers. My questions are: 1) Is there any special trick to getting the cover around the chain plate to come off? 2) How can I clean up the gray "stuff" to make a neater looking job? 3) Has experience shown that any particular sealant is superior to any other? (I say this after looking at the many choices available at my local BoatUS store). Any/all advice is appreciated. Thanks.