My boyfriend and I bought a house last year, and there was a wall running up the side of the stairs that seemed to be very drafty. He tore it apart, and found that the spray insulation had settled at the bottom and was no longer effective. He replaced the insulation, and attempted to fix the wall himself.. and did try very hard. However, he seems to think it just needs to be sanded now and then painted. I'd like to help him finish it, as it's been a daunting task..but I have concerns over whether or not he's doing it even slightly right. His mother has questioned his methods...but he won't listen to her. Can anyone here tell me if this is right, wrong, and/or what needs to be done to fix it/finish it? (Our house has old world plaster on all of the walls downstairs..and I'm thinking perhaps that was what he was trying to duplicate. However, none of the walls upstairs do, because they're only a couple years old... so the plaster texture isn't necessarily important)
*All of this is DRY. And it is drywall mud. Pictures were taken with a phone, so not the best quality