Was spot painting another area of my house yesterday... I'd taken down a big mirror (permanently mounted) over my fireplace and cleaned up the marks around it, patched the plaster around the boxes for the wall sconces, etc. I started by shaving down the brush marks with a razor blade and/or painter's scraper, then sanded with 80 grit, then 120 grit, patched some holes with patching plaster, went over everything again with 120, primed with Kilz 2, then finally finished with two coats of Benjamin Moore flat. (all paint was applied with a 3/8" nap roller, save for cutting in around the mantel, ceiling, and window trim.)
Here's the weirdness. I remember after painting, stepping back and noticing that there was a really noticeable spot at the upper left hand corner of where the mirror was where there was a lot of the texture of the old brush strokes from where the old paint had been cut in around the mirror. I distinctly remember mentioning this and making some comment about how I thought I'd done a better job prepping than that. Went back today to remount the sconces and now it's barely noticeable - if I hadn't known exactly what to look for and where I would never have seen anything. Basically, what you'd expect from a halfway decent prep job.
The only explanation I can think of for this is that the Kilz reacted somehow with either some patching plaster or the old paint and bubbled up, and then when everything dried it shrank back down to the wall. Sound plausible? Should I make a mental note to sand that area back down when I finally repaint the whole room, or not worth worrying about?
nate