I have a finished concert pillar in my living room that I need to be patched and pained. The pillar has final gypsum and paint on top of concrete. Since the concrete is chipped off I need to use a fast set repair mortar (such as QUIKRETE® FastSet™ Repair Mortar) to repair the concrete.
But I dont know if the gypsum material can be added on top of the repair mortar or not? is there a specific product that I can add on top to prepare the surface for paint ?