Dealing with Calcimine Paint ?

[Willa]

The bathroom has the worst plaster in the house. There looked to be many areas of paint failure, where the paint was pulling away from the wall or ceiling. I chipped a couple of pieces off, and underneath was a chalky pink paint, with traces of periwinkle blue paint on top. When I rubbed my fingers across it, there was white dust. From what I have read, this is old calcimine paint, which was not prepped properly for the layers of paint that went on top of it. This caused paint failure, and there were several efforts to remedy this by using plaster, as though it was the plaster that was cracking, not the paint.

I started scraping it last night, and almost the entire wall by the bathtub came off in brittle sheets. The wall below was in much better condition than expected. The repairs on top were worse than the wall below.

From what I have read online, I need to scrub the calcimine areas with soap and water several times, rinsing after each scrubbing, until the water runs clear. After several days of drying I can then patch the holes, then prime and paint.

My question is that there are areas where the new paint seems really stuck. I am scraping off what comes off easily to what needs some effort. Do I need to scrape off the stuck areas, too or if they are really stuck can they remain as is ?

BathroomStart.jpg (36.36 KiB) Viewed 6566 times

[Neighmond]

gently work the stubborn areas with a putty knife. I think you might use TSP at some point, the experts will confirm or deny this.

[Kashka-Kat]

Is what you're scraping off the calcimine itself, or only the layers above? Or both? I would try wiping with sponge of hot water - the hot water can soften up latex as well as dissolve the calcimine underneath and then it should come right off with scraper.

I think its worth it to get a smooth pristine surface. Is the brown your original calcimine layer or what yo're taking off? Had to laugh because that brown is exactly the color of my original layer throughout much of the house. Actually, its kind of growing on me and Im trying to decide which rooms I should keep brown.

I would recommend Gardz primer (by Zinsser) - its for "problem" surfaces and is about the only one I found that actually says 'calcimine" on the label. You want to get most of it off but I dont think its possible to get all of it - my first time painting, I didnt use it and the paint peeled. This time - it seems stuck on pretty well, five years later.

[Willa]

The chocolate milk color is the paint on the surface(ie latex). There are layers of oil paint under the upper coat.

The room will need some skim coating, and there are some recent plaster repairs under the latex that seem pretty stuck, too. Do I need to dig these out if they are well bonded to the wall surface ?

[phil]

Sometimes the fastest way is to bust out the plaster and drywall it. If you wan to save the plaster you can. They used that calcimine paint because fresh plaster is hard to get paint to stick to. I had one room where I stripped all the paint and wallpaper and the I just used a mop and lots of buckets of hot hot water. check the room below as you'll drip a bit but if that's OK you can just go ahead and mop like crazy for two days. then let it dry, then primer, then fix the plaster.. then skim coat.
I think I saw on the can that Kilz primer could be used over calcimine. I'd do my best to get what you can off then use a good oil based primer.. If you want insulation just get rid of the plaster, open the wall insulate and drywall. It depends where it is. is this an outside wall? is it like a museum or fancy Victorian masterpiece that you are restoring or just a square house where you want it to look nice again? I found lots of fine spiderweb cracks and I used drywall tape wet with carpenters glue and then bedded the tape with drywall mud and skim coated with drywall products. faster to break the wall but more original to save the plaster. Your choice. I'm happier with the rooms I opened and insulated than the one I restored the plaster in and now it's not insulated and kinda cold. It's the spare room so perfect for the mother in law i'm kidding ! lol

[Gothichome]

Willa, I would recommend not knocking off the plaster. When you get that far into the project. Do a little investigating of the patched in areas see if they used plaster or brywall filler. If filler it can just be sanded flush with the surrounding plaster. If plaster you may be able to remove the patch and start over. The whole point of of owning an old home is the maintaining the character and quirks that first attracted you to the home. I will agree with Phill though. At some point you may need (I hope not) to make the drywall/plaster decision but judging by your posted pics your a long way from that.

[Willa]

Gothichome, I can understand why people commonly choose drywall as a quick solution. Scraping then washing the walls is labour intensive and unpleasant to say the least, and I am not near the washing part yet. Knocking out all the plaster because 10% of the walls are in poor shape seems like overkill to me ? Particularly when the wall itself is in okay shape - it is the surface which was badly repaired.

I estimate the cost of repairing the bathroom walls to be approximately $ 200.00 worth of materials including primer and paint. This doesn't include my hours of labor. A couple of drywallers could knock out the plaster and get new walls up in a couple of days. The drywall probably would affect the profiles of the trim, making it nearly flush with the wall or worse. The rest of the house has old plaster, which I really like. I'm not enjoying the scraping too much. The first wall of failing paint came off very easily, and there's areas on the ceiling that are pretty bad.

My question was more that there are areas of what appear to be recent joint compound and mesh tape that are really stuck - and whether I should leave them alone or what ? I expect that I will have to patch and skimcoat to even out all the surfaces. It seems prudent to remove all the areas of paint where it is failing and not adhered to the plaster below, as that will continue to fail until the calcimine problem is dealt with ?

[nhguy]

Ben Moore makes an oil based calcimine recoater, I've used with great success. I second the washing with a sponge and scrapping as much off as you can with a putty knife. You'll be able to skip going to the gym, during your prep on calcimine washing. It's not an easy job for sure, but if you don't prep it the chance of paint failure is increased.

[phil]

"The drywall probably would affect the profiles of the trim, making it nearly flush with the wall or worse. "

I don't really understand why a lot of people are scared of removing the trim when doing wall repairs. Just cut the paint surrounding with a knife and pry gently around them. they will come off quite easily usually. In the event you do do get a crack or a split just glue them back while you have the pieces and they will be ok. Yea dont' bury the trim, that would look really bad
usually the casing nails will come with the trim. resist the urge to hammer them back and pull the nails out. Instead use plyers to pull them right through. you can use pliers or vice grips. If you happen to have a nail puller like this it makes the job easy.

this tool is designed to pull nails that are driven flush. you use the slidehammer part to drive the grippers so they bite into the wood either side of the nail and then it will pull them, You don't' need to use the slidehammer feature on your trim they work great for pulling nails through from the backside since you don't have the nail head to hook your hammer onto. If you hammer them back youll chip the wood a little on either side of the nail. If you are going to fill and paint them it's not such an issue but if you ever want to restore them to bare wood then you really don't want the chips. if you do you cna use colored filler but it's less damaging to pull them right through, as weird as it feels at first.

http://images11.palcdn.com/hlr-system/W ... 155293.jpg

If you dont' have a bathroom fan, it's worth thinking of installing one. Your bathroom will see more humidity than other areas. You could probably use at least blue drywall, or cement board, the plaster itself is more water resistant than drywall. If you use drywall filler for the repair, then put some good oil based primer on there to try to keep the moisture on the outside of the wall.

there is nothing wrong with restoring the plaster. You just don't' need to deal with the paint removal if you strip the wall instead. Once you've made your choice go in the direction you choose. Of course you wouldn't want to clean all the plaster off and then bust it down, that's just a waste of time. Once you've made the choice to restore the plaster and you don't' want insulation then you can decide if you will use drywall filler or if you want to use plaster for the repairs. If you skim coat with plaster you could have the same issue they did when they chose to use the calcimine. You may have to wait for the plaster fully cure before you paint or look at colored plaster instead of paint if you wan to go to that extent.

one technique you may try is this. do what you can to get the humidity up high in the bathroom, keep a kettle boiling and refill it for example. keep it steamy in there. close the door.
Take a box cutter and make a series of horizontal slits about an inch apart right across the wall. wet the wall down. it will take a bit of time but the water will get behind the other stuff. since the paint is water soluble you'll be able to get your putty knife between but you need to cut slits in order to get the moisture in there. You can nail a couple of old towels to the wall and wet them if you want. You'll easily fill any scratches or nail holes when you skim coat later. Once you get the humidity and moisture working for you, that stuff will almost be falling off on it's own. Capillary action will carry the water down from the slits and under the paint and paper. If you can control the water on the floor with plastic and towels you can use a garden sprayer and just go in there every half hour and wet the walls down. You won't hurt the plaster by wetting it temporarily. Check any rooms below and if you have valuables below use a plastic sheet to cover them from any drips that might run down there.

If you find filler on top of the plaster, be careful. if that repair was done prior to to about the 80's there is a really good chance the drywall mud contains asbestos. If you know the repair is later than 1980 then it might not be a worry. something about mesh tape was mentioned and it made me think maybe they didn't use mesh tape that long ago? when did it become available? maybe that dates the repair job? If you want to be cautious you can get a test for about 50 bucks. The actual plaster might not contain asbestos, if it is original. if you do nothing else then Just try not to breathe the dust from old drywall repairs. You might be inhaling asbestos if you do.

Right now I think you are doing it dry. It will be much easier when you get the water working for you better. the moisture will also help with dust issues. Put slits and mop the walls a few times. soak that paper. You will win

[Willa]

Phil, I am not going to drywall the bathroom. So far the areas where plaster has broken to expose the lathe are about the size of a mango, each. If one of the walls I haven't touched yet has more plaster failure I will patch that with drywall, I guess ?

Prying the trim off is a recipe for breakage and other headaches IMO. If it ain't broke, don't fix it.