NDDan
Guest
That tin filler is normally behind plate like you described and gave little to no trouble with normal rock door. With the sump it gets pressure like it wasn't designed for. Don't worry so much about it because with sump it just stuffs up. When we run sump we install a finger kit over sump to remove alot of the stressed from poor feeding over sump. We had to develop that kit to prevent the problems with feeding when rock sump is installed. Other manufatures have wires over sump and that is where we borrowed the idea. We also modify the side seals for rock sump so concave can still be swung open quickly and easily without removeing rock sump side seals. Side seals just need to be cut away to allow clearance for concave side frames to come down a small amount. Good luck