I've learned that it takes 3 coats...6" 8" and 12" skims the rest of bare dry wall. You end up skimming all bare dry wall. If you paint any bare dry wall don't it swell up and need sanding, mud and paint again? Isn't it: 6" knife for tape, 8" knife goes out from there, then 12" skims the rest of bare dry wall. ? With sanding in between.
Hello, and welcome to Home Improvement. Good question; keep 'em coming. And, you should probably take our tour so you'll know how better to contribute here.– Daniel GriscomJun 15, 2019 at 12:35
You do not need to have joint compound or skim coating spread over the whole wall before painting. The correct way is to use the compound and skim coating plus any needed sanding to cover seams, nails/screws and other types of repairs. Then you prep the whole wall using an appropriate sealer coat or primer paint. Lastly you come with your final paint coats.
1Unless you are going for a level 5 finish (perfectly smooth, usually reserved for walls exposed to harsh lighting conditions), then skim coating the whole wall is a typical way to achieve this. Though, I have seen other primer products in the past that advertise level 5 finish without skim coating, I have never tried one. I went the skim coat route for all the walls in my basement because “if you're going to do it yourself, do it perfect”, right? I was wrong — the extra labor of coating/sanding so many walls simply wasn't worth a minor improvement in the end result. Jun 15, 2019 at 14:13