Kevin, I'll be a little more specific, and since you've done a bit of drywall work you probably already know this, but I've already gotten a couple of emails from readers asking what "setting compound" is. So...there are essentially two families of drywall compound. Premixed mud in the infamous drywall bucket that hardens by drying, and "setting compound" that hardens via a chemical reaction. Premixed mud is water soluble. If that's what you have on your cement board, I'd take a sponge to wet and soften it and a bristle brush or taping knife and get rid of it. If what you have is not water soluble (it doesn't soften when wet) then it's a setting compound. Setting compounds come as dry powder, you add water to them. Add water, mix, and the chemical hydration reaction starts. Some are designated by a certain amount of working time, like "20-minute mud". You have about 20 minutes to get it on the wall before it gets to tough to work with. It's also referred to as "hot mud", I always figured that's because the chemical reaction gives off heat after it's mixed with water. So...if it's water soluble, get it off your cement board. If you tile over water soluble compound, the moisture in your thinset can be absorbed by the compound, which can soften the compound and destroy the bond between the tile/thinset and the wall. If it's a rock-solid, non-water soluble setting compound, I'd say it's okay to tile over. Mongo

"He said"? The drywall man from he!!. They're not really nail pops. The joint compound over them is raised. It flicked out when I messed with it. They're definitely screws underneath. I didn't notice if the paper was broken or not. It's surrounded by mud. When you put new screws in, how do you make sure not to break the paper? I've been anchoring old nail pops on the walls and it seems to have a mind of its own how far it ends up setting in. Sometimes have to press on the drill to keep the screw moving. Looks like I will have to add others if there is no support from broken paper. The nails are deeper too. I used a nail set to put hammer them back and a screw over the edge to hold them. But all seems to be standing okay. This post was edited by snookums2 on Mon, May 6, 13 at 9:22

Setting compound comes in paper bags labeled setting type compound, with a time on it. Get the longest time you can find,90 minutes or greater.Home depot sells setting compound that sets up in 110 minutes . The time is the working time after you mix water with the powder. After the working time is up whats left in your bucket solidifies. That means you have up to that time to clean your tools and bucket out. When working with setting compound take extra care cleaning your tools and bucket. any residue of the previous batch will cause the new mix to solidify very fast. So just clean everything thoroughly. The nice thing with setting compound, is the fact it doesn't shrink when it dries like the premixed does. You then need less coats.

No. Leave a gap between the tile and top equal to the thickness of the grout lines. Fill the gap with color matched silicone after you're done grouting. I'd change that double bowl sink to a single. I'll bet this will fit nicely.