Hallow hit the nail on the head. You have to have the area to be primed scuffed up. The primer needs some teeth to bite into. The metal cannot be cold. The area must have NO wax or grease what-so-ever. Use a good wax and grease cleaner such as in prep-sol to clean it. If the primer is shrinking either you have wax or grease and it is seperating from it, or you have the primer mixed incorrectly. Check the directions, they are printed on there for a reason.