You’ve heard me say, on every room, that I degloss the trim before painting it. Why? You have a couple options for good adhesion of the new paint over the old: cleaning and sanding, stripping and cleaning, or scraping and cleaning. If the old paint is in reasonably good condition, a light sanding will do. If it’s pretty built up, you most likely will want to strip it. And if it’s beyond those things, you will need to scrape the flaking paint to provide a seam-free surface for your new paint. Either way, you have to clean it too. The deglosser will do the cleaning and the job of either the sanding, stripping, or scraping. Because it’s a harsh solution, you must wear gloves. But because it’s a harsh solution, it provides a lot of elbow grease of its own.
I’m not sure what on earth my dad was thinking when he painted this room. My guess is, he was getting tired of maintaining the home and just slapped some latex paint over the old stuff without doing any of the above. Bad idea. Because of this, the top coats were removing the bottom coats and the whole thing was chipping off. I didn’t want to remove all the old paint due to time and the reasonable condition of the rest of the trim. So I scraped a little with just a plastic scraper, to remove only the loose edges, then cleaned and smoothed it all down with my trusty deglosser. It penetrates and bonds the paint layers as well as provides a “toothier” surface for new paint.