Interior sheet rock surface with ‘knock’ down plaster covering the rock. Already has one coat of latex paint.
NO, YOU HAVE TWO CHOICES; YOU CAN 1 SAND THE WALL FIRST BY KILLING THE SHINE OF THE LATEX AND THEN PAINT THE ENAMEL. OR 2 YOU CAN PAINT THE WALL WITH A SEALING PRIMER LIKE KILZ OR BIN. SEAL FIRST THEN PAINT THE ENAMEL.