Dealing with Calcimine Paint ?

[Texas_Ranger]

I usually stop when there's no colour left or barely any. Last time I did that I still had some bubbling trying to skim-coat the walls afterwards so I'm not 100% sure what to tell you (that was in the hallway of a 1960 apartment where we found the original paint behind some huge pieces of furniture). Never tried soap or other cleaners, just plain cold water. I think what I did was try to get most of the paint off with a stiff scrub brush and lots of water, then wiped everything down with clean, dry rags (we had plenty of them since the PO hoarded old bedsheets and whatnot for cleaning).

Depending on how much water you use you should get a slightly sticky sludge or runny liquid. For scraping the bulk of the paint I use fairly little water so the paint comes off in soft flakes. If it's old enough it might even come off dry - it's cellulose glue and that seems to break down with age.

I thought I had that in my profile but I'm located in Vienna, Austria, Europe (southeast of Germany). DIYers here mainly switched to (usually flat) latex paint (called emulsion in Europe since most varieties don't actually contain any latex) back in the 70s while painters switched from cellulose-based paint to acrylate-based. That's still a somewhat water-soluble binder with lots of chalk and clay. The main difference between the two is that the latter can be carefully cleaned with a damp cloth while the forme comes off the wall as soon as you touch it with something wet. Acrylate-based also stores better (with added fungicides), cellulose-based was only ever sold in powdered form. Cellulose-based is required by historic preservation societies for painting ornamental plasterwork because it can be washed off without damaging the historic plaster. The big downside is that you can't really paint over it and need to wash it off every time you repaint. If you don't wait too long in between (say every five or ten years) you can but then the glue breaks down and you either get bubbles or the old paint sticks to your brush straight away. You also need three coats most of the time while quality emulsion covers with just a single coat. On the plus side cellulose-based paint (which is currently making a comeback among the eco crowd as "clay paint") is zero-VOC and acrylate-based is very low-VOC.

[Kashka-Kat]

Im dealing with something similar inside a circa 1920s painted maple cabinet - the paint is hideous red that dissolves in water (looks like blood- ewww) I was scrubbing and scrubbing to the point where the wood was starting to warp from all the water... so I tried denatured alcohol thinking I would just clean it and paint over with the afore-mentioned primer. But the alcohol TOOK OFF even more of the ugly red paint - it liquefies just like shellac, and then if I don't get it all off it starts to stiffen up again, just like shellac! So now Im scrubbing with denatured alch and steel wool to remove more of it. I wonder if there wasnt some sort of shellac based paint or something..??????? Was shellac perhaps added to flat calcimine to give it more of a sheen? Anyway, you might experiment with alcohol and/or nontoxic paint removers or whatever to see if anything removes it quicker/more thoroughly. Otherwise - at least scrubbing with water doesn't smell up your house and it can be a sort of meditative task sometimes.

[Willa]

Oh wow - that red paint stuff sounds awful !

I have been skim coating the stairwell, so I haven't been scraping the bathroom walls for a couple of days. I am definitely dreading the washing down step. The blue and pink paint look so similar to tempera paint. I am guessing that some washing down had taken place before the oil paint on top - just not enough. In the interim I have a bathroom with lots of rose colored dust everywhere.

It helps to know what to expect with the scrubbing removal - how far to go.

Texas Ranger - from your description it sounds like there are no upsides to this type of paint with the exception of being able to wash it off decorative plaster details.

[Lily left the valley]

It came to mind, reading responses...

If the scraping is turning into a PITA due to layers, would it be worth pulling out something like a surform shaver from the ol' toolbox? Or would that make it harder to tell when you're past the calcimine? I was thinking that maybe the surface break might leave a grip base for a skim coat over, but I'm also wondering if it's just not a good idea period.

[Texas_Ranger]

If this is actually what we're all thinking you shouldn't have any trouble scraping it all of in one go, no need to break out power tools! Usually when the paint is damp the scraper just goes *zzziiiiiip* and takes off the bulk of the paint. Getting the remaining glue off the walls is where it gets a bit tedious and messy.

[Willa]

This is what the calcimine paint looks like as I am scrubbing it off. The color is much darker when it is wet.

I have been using two buckets of water - one with hot soapy water, the other with clear warm water and rags. I have been saturating the surface with hot soapy water, then use a scrubber pad to get as much paint as possible off the plaster. Then I wipe off what is loosened and rinse with a rag and clear water. When it is dry, there is a very slight layer of calcimine dust (v.s. a chalky hand before ). On the areas I have cleaned, let dry, then patched, there has been no obvious bubbling (ie calcimine reacting with plaster or joint compound). I will wait and see how much surface area gets the final skim coat before re-rinsing any exposed areas ?

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[Kashka-Kat]

Oh that's just lovely! Looks like youve got some bloody red streaks going on too.... as do I with my project.

In a way it kind of looks like old wheat paste wallpaper paste residue which dissolves in water ... which I had many sq ft to contend with.... but I don't know if that would feel "chalky" more like a rough texture.

In any event it looks like you're doing a great job So satisfying to get off all that old gack.

Ive not been able to get off my calcimine from my walls as thoroughly as that. Maybe Ill more scrubbing, maybe just use Gardz again.

[Willa]

This calcimine paint is kind of a mystery. The woman at the Benjamin Moore store with 20+ years experience was completely unfamiliar with it, as were the folks at the local hardware store, and an experienced contractor.

I wonder if there are regional differences as to the appearance and behaviour of this paint due to varying recipes/manufacturers ? Was it sold dry and mixed by the user, or sold in cans like conventional paint today ? Does anyone know ?

I dealt with old wallpaper paste at two places I lived, and that was more brownish/tan, and stickier, with no chalky surface. As I scrub away, I ponder how they got the blue paint on top of the salmon paint - as it is very water soluble.

The baseboards and floor are a big mess, with the dusty residue reactivated with the soap and water, and lots of run-off drips. It's hard not to experiment with turning the shower hose on the whole room !

[Mick_VT]

It is often called "distemper" maybe its a regional thing with the name? I seem to recall being told it was sold in solid form (whiting) and mixed on site (addition of water, glue and color)

[phil]

i sometimes ask what to do about calcimine paint if I go into a paint store and get help. I find often questions like have you used this product before? are fair and often they will just go find the one person who knows the trade if you ask that. Some paint store employees can talk the talk but often they go from counter help to giving advice without really being a painter. If you throw a question at them like how do I paint over calcimine and they don't' know what that is it sort of says in a nice way "go get help" Painting is a trade but unless they work in a union environment it is probably rare that they get asked for any sort of ticket so probably most of the painters out there shouldn't go around calling themselves tradespeople without completing their apprenticeship but like with drywall and roofers, it's often the case.
They should be familiar as some paints say they are recommended for calcimine. Read the label on Kilz or other primers near it. You will probably see a note about calcimine paint right on the can. I can't imagine any experience painter that works on old houses not knowing what calcimine is but it isn't' a current product so if you get this dumbfounded look then either they haven't been around old houses much or they just learned from selling the products and not from using them, big difference. Some paint stores do give extensive training on newer products via the paint companies but only know those products whereas a painter who is a tradesman would have used all sorts of products through their career and would be able to offer comparisons from experience.. It's a fair question to say are you a painter and then when they say yes to say do you have a ticket? have you done your apprenticeship? no then can you ask a painter ? do you have an employee on staff who is a trades person? I bet fewer than 5% of paint store employees could produce an actual ticket. Now if you asked those questions to a plumber or electrician it would be different and most are or they don't' call themselves plumbers or electricians but people think painting is simple and don't recognize the need for a ticket in the same way.

You are doing fine it is just a lot of washing and I wouldn't worry about every little bit if you use the kilz or something like it as a first coat. Just don't paint until it is fully dry or that might cause issues. If it feels chalky then keep washing. when the water isn't getting dirty anymore you are done. soap might help but I'd make sure you got the soap all off. you can seal it in with good primer then do your skim coating over top of the primer and primer again when you are happy. It's another coat but I find that it is easier to get a perfect job by doing it that way. I just get it close and then primer and then i can see the surface and where I have put my new mud more easily. I find if I don't' do it that way it is too easy to sand more off than I really wanted to, or to forget where the new mud is and find myself re-sanding what's already sanded and producing hollows as a result. I'd suggest a good oil primer or something like Kilz and then you can use the cheaper primer on any subsequent coats. I just bought some run of the mill primer sealer over the weekend and noticed the others like Kilz or other types of hiding primers were about double.

there is a good article here:
http://www.plasterlord.com/notebook/fcalcimine.htm