Serious question, why does everyone skip the primer step on drywall patches?
I've been fixing small holes in my walls for a while now, and I keep seeing people online just mud, sand, and paint. I did that for three patches in my hallway and every single one showed a shiny spot or a color difference after a month. My buddy who paints houses in Toledo told me flat out, 'If you don't seal the mud with a proper primer, the paint soaks in different and it will flash.' He was right. I went back, used a basic PVA primer on those spots, repainted, and now you can't tell they were ever there. It adds one extra step and maybe 30 minutes of dry time, but it fixes the problem for good. Has anyone else had this happen, or found a different primer that works better?