I’ve run into the same thing on a bunch of old houses. Tried a fancy eco primer once and it just bubbled right off this 1920s dining room wall—looked like a science experiment gone wrong. Sometimes you just have to mix old-school with new-school, you know? The walls have seen it all.
Honestly, I get the urge to mix old and new, but sometimes the “old-school” stuff just traps moisture and causes more headaches down the line. I’ve had better luck stripping back to bare plaster, then using a mineral-based primer—less bubbling, more breathability. Those eco labels can be hit or miss, but there are a few that actually play nice with historic walls. Just gotta dig a little deeper sometimes...
Honestly, stripping back to bare plaster sounds like a pain but I get why it works. I tried using one of those “eco” paints straight over old limewash and it just peeled off in sheets… total waste of time and money. What worked for me was: 1) scrape everything back, 2) let it dry out for a few days, 3) mineral primer, like you said, and only then the paint. The eco labels are confusing—half the time they’re just marketing. I just check if it’s vapor-permeable and non-acrylic, that seems to be the key for old walls.
Yeah, I’ve been burned by those “eco” paints too. The first time I tried one, I skipped the primer because the label said it was “self-priming”—big mistake. It bubbled up and flaked off within a month. I ended up having to sand everything back, which was a nightmare with all the dust.
What’s worked for me is pretty similar to your process: strip it down, let it breathe, then use a mineral-based primer. I’ve found silicate paints are usually a safe bet for old plaster, but you really have to check the fine print. Some brands sneak in acrylics or vinyls even when they’re marketed as “natural.”
Honestly, I wish the labels were clearer. Vapor permeability is the main thing I look for now, too. If it doesn’t say “breathable” or list the sd-value, I just move on. It’s a bit of a minefield, but at least once you find a system that works, you can stick with it.
Yeah, those “eco” labels can be a total headache. I’ve had the same issue with so-called self-priming paints—never again. My go-to now is: (1) sand or strip old layers, (2) let the surface dry out fully, (3) use a mineral or silicate primer, and (4) double-check every ingredient list. If it doesn’t mention sd-value or breathability, I just put it back on the shelf. Sometimes I’ll even email the manufacturer if I’m not sure... Annoying, but better than redoing a whole room. Marketing can be so misleading with this stuff.