Primer & paint questions

No need to sand after priming. If there are rough spots (such as from prior patches), sand those before you prime.

However, before you apply any primer to your walls, I'd wipe them down. Use water with a bit of dishwashing detergent to cut through oil and fingerprints. Just don't use so much detergent that you end up with suds on the walls. The goal is to get the walls clean and leave a good surface for the primer. And if you do any sanding, do it before you clean the walls.

One coat of paint may be sufficient on top of primer, but I'm of the mind that two thinner coats are better than one thick coat. You'll almost certainly need two coats if you're painting a deep color.

For me, the biggest hassle with painting is the prep work, and that doesn't change if you're doing one or two coats of paint. Might as well do a high-quality job if you're going through the hassle.

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Apply primer once the sanding is all done. Always prime over raw plaster or sheetrock but otherwise there is no need to prime -inless of course you are switching between latex and oil. As for number of coats, it depends on how the coverage looks after each coat. Most times you'll need a high quality paint and minimal color difference to get away with one coat. I've used both BJ brands with success and frankly don't care enough to go deep inside the molecular properties of each to formulate a pro/con position. I know, I know, not very 2010ish of me. Make sure you spend a lot of money and you'll be fine.

inless? I like it, lets leave it

Why would you sand the walls if they are new? Sanding is usually done to smooth out imperfections.

Most painters will say don’t prime unless it’s brand new sheet rock or switching from dark color to light color and vice versa. Nevertheless, I prime. 1 coat of paint over primer is generally enough unless it’s a dark color, which sometimes can be a hassle.

joseesq-usually when you paint there is some plaster repair of the walls to do beforehand, hence the sanding remark. If no plaster, no need to sand.

The sanding was in reference to some plaster work to cover up nail marks and small holes in the drywall. My walls are basically off white now, and I'm sticking to light pastel colors so sounds like 1 coat of primer and 1 coat of high quality paint should do. Alternatively, I gather I can do two coats of paint, which is more costly and I'm not sure will yield more visible results. Thanks for the responses.

I disagree with Spinnaker1 as to when to prime. If you are making a big color change, you should also consider tinted primer as the first coat. Also prime is walls have dirt/stain issues despite wiping. Primer will seal in many types of stains that could otherwise show/leak through.

I would insist on 2 coats. Otherwise, when the light hits a wall just so, you will keep finding areas that weren't covered sufficiently as the weeks and months go by.

"Also prime is walls have dirt/stain issues despite wiping." ... agree, and I'd also consider washing walls/trim first, then tacking off residue. Otherwise you're basically applying latex primer to a film of oily sooty residue, compromising adherence.