As most of you know the screw that holds the battery in place is hollow....because it is screwed into a closed threaded recess in the battery. If it was solid air pressure would prevent it being fully fastened. BUT that hollow allows grit and sand to get onto the threads. So one way to stop that is with a bit of sponge pushed into the hollow. I also grease the threads to help ensure further blockage from dust etc and ensure the right torque is applied. (thread lock is not a good idea since it would be very difficult to clean out kf the battery threaded insert to re apply).