You might want to try Slick Sand, or feather fill. They are like spray bondo. I have used the slick sand. It didn't like the DP90 underneath. Wouldn't set up. Had to scrape it all off. It works fantastic on bare metal. Very easy to sand, but still hard as heck when it sets. Feather fill is supposed to go over DP 90, but still has the same attributes as slick sand. Don't leave it in your gun. It will ruin it. Also make sure you seal leftover product air tight, or it will harden.
