Had the worse experience at work I can remember fora long time on Friday. I was skimming over a artex ceiling 28sq m on my own , , the bloody thing was on the turn after 10 mins , I gave it 3 coats of pva over two days previous and it sucked like a goodn. By the time.i was 3/4 way through putting the first coat on it was going off where I started . in the end i just got it as flat as I could and gonna give it another couple of coats of pva and reskim it.. Done loads of artex ceilings , heard a few horror stories but first time it ever happened to me . In 15 years ..