i've used jbw on a motorcycle engine block, a car battery, all kinds of stuff. the only thing i put it on that did not work well was on the bottom of an old john boat, i put it around some rivets when we stepped on the inside the whole patch of jbw would crack away from the bottom of the boat. if the bottom of the boat had been totaly stationary i am sure it would have worked. if area is not stable you might want to go with the pliable caulking idea. just my two cents worth.