Would your HO accept a skip trowel or back trowel? both are quick and don't require a hopper and compressor.Okay, sanded it with 150 lightly, rolled on thinned mud. The roller skipped in several places and wouldn't stick in others, so I do let it dry a bit before reapplying.
And then the paint began to bubble in four-five places!!!!
Cut the bubbles off, and it looks like the paint wasn't even stuck down.