The bubbles are usually from not mixing the mud well enough or not applying it with enough pressure. It is not unusual to see lots of small bubbles on the first coat. Here’s a little trick for your third or final coats of mud. Mix a small amount of water and Ivory dish soap into your mud and mix well.Click to see full answer. Accordingly, why am I getting bubbles in my drywall mud?The bubbles are usually from not mixing the mud well enough or not applying it with enough pressure. It is not unusual to see lots of small bubbles on the first coat. Here’s a little trick for your third or final coats of mud. Mix a small amount of water and Ivory dish soap into your mud and mix well.Subsequently, question is, why does drywall mud bubble on paint? Any air coming from the drywall compound fissures will just bubble through the wet film. After a few hours the cracks in the mud also dry out. The water will eventually evaporate from the fissures and by the time of the next paint job they will be ready to produce blisters all over again. People also ask, what causes plaster to bubble? Uneven drying – uneven drying, or a lack of ‘curing’ time for your plaster or stucco wall can also contribute to nasty air bubbles. The trapped moisture inside will cause the paint to blister due to the presence of water that attempts to come out as the plaster and paint as they both drying.How many coats of drywall mud do I need?Apply three or more coats of very thin compound rather than one or two heavier coats. Yes, it takes time for the compound to dry, but don’t try to rush the drywall taping process along by applying fewer, thicker coats.