Marine sealants (caulk) can be hard wo work with. 3M 5200 is especially difficult if your trying to get a nice looking bead. I mostly use Sikaflex 291LOT or a marine store polyurethane. Boatlife isn't bad, either. Those are more flexible and less adhesive sealants than 3M 5200. Like most other polyurethanes, Sikaflex is easier to shape with a spreader and clean up with a damp paper towel so long as you work with it before it starts to cure.
