I'm getting ready to do some skim coating in my kitchen to smooth the walls out (we're smothing to tile some areas and paint others)- there are 3 different issues: 1) existing orange peel in some areas 2) areas where previous owners did a not-so-great job of trying to smooth orange peel 3) rough joints under cabinets where new dry wall was hung My questions: 1) I've previously had great luck doing skim coating on small repair areas (approx 20x5") with pre-mixed joint compound- is this ok to use on large wall areas, or do I need to mix from powder? If so, what should I purchase? 2) I've read many posts about thinning down the j/c to make it easier to work with, and even something about adding some dishwashing detergent to make it smoother- opions? 3) This is the first big area I've done- any other suggestions or tips a first-timer may not think about?

my husband and i tried knockdown the other day. We need to knockdown our bathrrom ceiling. We bought a hopper and a wide scraper and practiced on a piece of drywall that had been painted. first we waited 15 min and it all smeared then we tried again and waited 30 min and a little better then we tried again and waited 45 min. It looked ok but not great how do you get it not to be quite so smeary? Does it make a difference if it is on a painte surface? We had to keep making the mud thicker and made the spray smaller to get the bigger blobs we wanted. Should you keep spraying till all visible wall is covered? How do you know when it is time to scrape? Please help, we want to do this project this weekend. Thanks for any information.