Complete 2 Systems worked on US Payne Straight A/C: replaced case coil. Recovered ref. To remove ductwork and case coil took us more time than usual due them having a bunch of screws and probably a 1/4 inch layer of mastic that was hard as cement. Removed old coil. Installed new case coil. Had to repipe copper lines and drain line. Leak tested system. Pulled vacuum. Added 7 lbs of 410A.