There is a lot of discussion over air bubbles showing up in drywall mud and a lot of confusion. So I thought I would clear it up for everyone.
This should only happen when mudding over a painted surface. It’s not the way you mix, or how much water you use. And there is nothing you can do to stop it. If you’re not good enough to finish in 2 coats, sand between 2 and 3. After your finish sanding, thin out some mud, add a LITTLE RED chalk to the mud to make it a faint pink coulor that doesn’t show through paint and swipe to fill holes. Scrape it as tight as possible, we’re filling the holes not making more sanding work. Afterwards sponge sand everything pink with a light shining downward. You might miss some holes but these can be touched up after priming with dry-dex or spackling and not have to be reprimed.
Since you are mudding over painted walls I’m assuming most of you are doing renos and not new construction. You will likely be doing both mudding and painting.