Painting your walls without poisoning the planet?

I’ve run into that same issue with old plaster - sometimes the casein just doesn’t want to bond, no matter how well you think you’ve cleaned it. I usually give the walls a light sanding after patching, then wipe them down with a barely damp cloth to get rid of dust. If it still seems iffy, I’ll hit stubborn spots with a mineral primer (the eco-friendly kind). It’s not always necessary, but on really patchy or glossy areas, it makes a difference. Old houses... never quite know what you’re getting into. You’re definitely not alone in having mixed results.

Mineral primer is a real lifesaver, especially when you’re dealing with those mystery stains or weird glossy patches that just laugh at your best cleaning efforts. I’ve had some luck with a clay-based primer too - smells a bit earthy, but it’s pretty forgiving on old plaster. Honestly, sometimes I feel like these walls have seen more history than I have and they’re not about to let go of it easily.

I do think sanding helps, but I’ve learned the hard way not to overdo it - one time I went a little too enthusiastic and ended up patching more holes than I started with. Old houses really are like a box of chocolates... except sometimes you bite into one and it’s just dust and horsehair.

Eco-friendly paints have come a long way, but yeah, they can be finicky. I try to stick with mineral or casein when I can, but if nothing wants to stick, I’ll admit I’ve caved and used a shellac-based primer in the past. Not ideal, but sometimes you just want to get the job done before the next century rolls around.

Those “mystery stains” are the bane of my existence, too. I’ve had more than one rental where no amount of elbow grease or eco-friendly paint could get a wall to behave. I had to laugh at this:

Old houses really are like a box of chocolates... except sometimes you bite into one and it’s just dust and horsehair.

I get the urge to just grab shellac and move on, but I’ve found it can cause headaches down the line - especially if you’re dealing with tenants sensitive to fumes or allergies. Sometimes a good oil-based primer (yeah, not the greenest, but less intense than shellac) does the trick without quite as much environmental baggage. It’s a trade-off, but I try to weigh long-term durability against immediate convenience. Anyone else run into issues with shellac yellowing over time?

Title: Painting Your Walls Without Poisoning The Planet?

I get the urge to just grab shellac and move on, but I’ve found it can cause headaches down the line - especially if you’re dealing with tenants sensitive to fumes or allergies.

That’s exactly why I stopped using shellac years ago, even though it’s tempting for quick fixes. The off-gassing is brutal, and in older buildings with poor ventilation, it lingers way too long. Honestly, the yellowing is only part of the problem - I've seen it get downright amber after a couple years, especially in spots that get a lot of sun. That’s not what anyone wants when they’re trying to keep things looking fresh.

Oil-based primers are a bit less harsh, but I still get stuck on the environmental trade-offs. VOCs are lower than shellac but still not great, and cleanup is a pain. I’ve been experimenting with some of the newer water-based stain blockers - some of them actually perform better than I expected, especially on smoke or pet stains. They’re not always as bulletproof as oil or shellac, but at least I don’t feel like I need a hazmat suit.

Has anyone found a water-based primer that really holds up against tough stains or odors? Or is there some trick to making them last that I’m missing? I’m all for durability, but it’s hard to justify using products that make my workspace smell like a chemical factory for days… especially when tenants complain about headaches or allergies.

Curious if anyone’s tried any of those plant-based or “natural” primers? I keep seeing them pop up, but I’m skeptical about whether they actually work on anything more stubborn than drywall patches. Would love to hear if there’s something out there that doesn’t force you to choose between your lungs and your walls.