# Milk Paint (lime casein paint)



## JourneymanBrian (Mar 16, 2015)

Ive been experimenting around recently with some lime (calcium hydroxide) paints.

A few weeks ago I plastered a surface with lime/cement plaster (stucco) and applied 3 pure limestone coats in the "fresco" technique, applying the first coat to the fresh plaster, and the subsequent coats while the paint was still cool to the touch. 
Worked well, no chalking at all.

Today I tried mixing a so called milk paint, which made by activating casein (clotted cheese) with an alkali (slaked lime) in a ratio of 4:1, creating a water-insoluble binder.
To this you add 3 times as much pigment as you have binder ( I used lime chalk).











Ill have to try it out on a wall and post the results. Unlike the pure lime, it is not particularly antifungal, as I understand, so it shouldnt be used it wet areas.

Apparently, this binder-creating reaction works with a lot of proteins, also egg white and blood, for example.

Next up on my list is the blood version, which apparently is the reason why so many barns are painted red (seriously)


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## daArch (Mar 15, 2008)

Although all these calcimine, casein, milk, blood paints have great properties, they become a nightmare when someone in the future wants to apply a modern day oil or latex paint on that surface.

The calcimine/casein paints were great on RAW plaster ceilings because they were dead flat, filled (actually HEALED) cracks, leveled real well, and easily maintained.

Milk paints were also FLAT and adhered very well (protein is a very strong adhesive). And the blood paints you mentioned were actually just a by-product from slaughtering farm animals.

It's great to be able to recreate historical coatings, and I applaud your inquisitiveness and research :thumbup:, but please understand we ain't living in the 18th century and some day someone is going to want to apply 21st century coatings. 

I've stripped enough of ALL the above and will do all I can to discourage the use of them unless you are applying to a historical building to retain historical authenticity forever.


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## I paint paint (May 4, 2014)

Arch, you saying BM Calcimime Recoater (306) doesn't live up to name?

I also think it is great he is recreating historical coatings, and think it doubly awesome he is sharing it here with us.

If anything, I want JourneymanBrian to go an extra step further and put some (306) on it to see how it reacts. If promising, then put a 21st century finish coat over the (306).

Keep going!


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## Gough (Nov 24, 2010)

daArch said:


> Although all these calcimine, casein, milk, blood paints have great properties, they become a nightmare when someone in the future wants to apply a modern day oil or latex paint on that surface.
> 
> The calcimine/casein paints were great on RAW plaster ceilings because they were dead flat, filled (actually HEALED) cracks, leveled real well, and easily maintained.
> 
> ...


When I teach finishing classes for the students in the furniture program at the local university, one of the finishes that we spend a fair amount of time on is milk paint. It has a number of great attributes. It's green, it's relatively innocuous, repairable, easily top coated with oil, etc.

PS. Another finish I teach them about is soap...just soap. Clean up is a snap.


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## daArch (Mar 15, 2008)

I paint paint said:


> Arch, you saying BM Calcimime Recoater (306) doesn't live up to name?
> 
> I also think it is great he is recreating historical coatings, and think it doubly awesome he is sharing it here with us.
> 
> ...


I too think it's great and admirable he's recreating these finishes. I wish Calcimine/casein ceilings were always kept as is. They are fabulous coatings . . . . if one don't try to PAINT over them


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## daArch (Mar 15, 2008)

Gough said:


> When I teach finishing classes for the students in the furniture program at the local university, one of the finishes that we spend a fair amount of time on is milk paint. It has a number of great attributes. It's green, it's relatively innocuous, repairable, easily top coated with oil, etc.
> 
> PS. Another finish I teach them about is soap...just soap. Clean up is a snap.


Again, it's a very durable finish, and a bane if ever needed to be stripped.

But, I'm not sure green is the only color is can be made :whistling2: :jester:


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## Gough (Nov 24, 2010)

daArch said:


> Again, it's a very durable finish, and a bane if ever needed to be stripped.
> 
> But, I'm not sure green is the only color is can be made :whistling2: :jester:


Not sure why you'd need to strip it. We've gone over it with oil primer without any issue.


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## daArch (Mar 15, 2008)

Gough said:


> Not sure why you'd need to strip it. We've gone over it with oil primer without any issue.


can't remember WHY we stripped a banister painted with milk paint (my memory from the early 70's is a little hazed) but we did it per the HO's request. I DO remember it was one of the toughest coatings I've ever stripped.


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## cody o'mick (Jul 2, 2015)

daArch said:


> can't remember WHY we stripped a banister painted with milk paint (my memory from the early 70's is a little hazed) but we did it per the HO's request. I DO remember it was one of the toughest coatings I've ever stripped.


Restoration Rehabs on historical properties. I did the same thing on window sills and pickets/railings in the HQ of the Daughters of the Confederacy in Richmond Virginia some years ago. Haven't seen it since (and not regretting it )


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## JourneymanBrian (Mar 16, 2015)

Thanks for all the comments, guys.

As to the repainting issue, are you sure youre not confusing with distemper paint (wallpaper paste as binder) 
I ask especially because someone mentioned old ceilings, which here Ive only seen with distemper paint.

Ive noticed the coat can be worn off with strong abrasion + water, but it wont chalk when rubbed with a wet finger like distemper paints do.

Supposedly this is due to the formation of water-insoluble soaps in the reaction of casein/lime.

Maybe paint thinner would dissolve the coat, I havent tried.

Another subtlety is that "milk paint" is also used to describe casein-oil tempera paint, in which the milk functions as an emulsifier of water+oil and/or resin.

I know this topic is more academic than practical, but the green painting forum is so seldomly used, I thought Id give it a bit of stimulation


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## I paint paint (May 4, 2014)

daArch said:


> I too think it's great and admirable he's recreating these finishes. I wish Calcimine/casein ceilings were always kept as is. They are fabulous coatings . . . . if one don't try to PAINT over them


This is our chance to prove Jack Ford correct!

http://www.painttalk.com/f2/gardz-coverstain-45170/#post834970


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## daArch (Mar 15, 2008)

JourneymanBrian said:


> Thanks for all the comments, guys.
> 
> As to the repainting issue, are you sure youre not confusing with distemper paint (wallpaper paste as binder)
> I ask especially because someone mentioned old ceilings, which here Ive only seen with distemper paint.
> ...


As you allude, there can be confusion between these coatings: casein, milk paint, distemper, and calcimine. 

First, calcimine is very similar to whitewash but with a glue - sometimes casein. And with use of milk protein (casein) as the glue, immediately a confusion arises between it and casein paint.

And since casein is milk protein, there exists confusion between casein paint and milk paint. 

And since distemper is chalk and any number of ill defined glues . . . . 

Well, I can understand how the terms are confused. 

In my experience, surfaces coated with a lime (chalk) based coating need to have it washed off before an oil or waterbased paint is used.


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## daArch (Mar 15, 2008)

I paint paint said:


> This is our chance to prove Jack Ford correct!
> 
> http://www.painttalk.com/f2/gardz-coverstain-45170/#post834970


I'll let YOU test it out. :whistling2:


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## JourneymanBrian (Mar 16, 2015)

daArch said:


> As you allude, there can be confusion between these coatings: casein, milk paint, distemper, and calcimine.
> 
> First, calcimine is very similar to whitewash but with a glue - sometimes casein. And with use of milk protein (casein) as the glue, immediately a confusion arises between it and casein paint.
> 
> ...


The binding agent is the key factor here:

(pure) lime paint: lime

lime/casein paint: water-insoluble glue or water-insoluble glue plus lime, depending on share of each in mixture.

casein tempera: oil (and/or resin)

distemper: wallpaper-paste (reversible, water-soluble glue)

Lime chalk (or any other anorganic pigment) can be used as pigment in all of these.
In pure lime, you dont need additional pigment, as its already white.

The blood paint works the same way as the lime/casein, substituting blood for casein.


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## daArch (Mar 15, 2008)

JourneymanBrian said:


> The binding agent is the key factor here:
> 
> (pure) lime paint: lime
> 
> ...


as I said, much confusion around the world as to the definitions and ingredients. :thumbup:


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## JourneymanBrian (Mar 16, 2015)

yeah the problem is a degree of chemistry knowledge is needed for understanding.

I had to read into it a good deal myself.


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## DrakeB (Jun 6, 2011)

I paint paint said:


> Arch, you saying BM Calcimime Recoater (306) doesn't live up to name?
> 
> I also think it is great he is recreating historical coatings, and think it doubly awesome he is sharing it here with us.
> 
> ...


I'm not sure I'd trust the 306. I thought it said on the TDS to strip first even though it's a recoater, but I must have remembered wrong. Still, the problem with calcimine for oil based products isn't adhesion of the oil to the calcimine, it's the adhesion of the calcimine to the wall after the strain of the oil being applied and drying. I think houses with calcimine should just be burnt down


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## JourneymanBrian (Mar 16, 2015)

ok but calcimine doesnt really adhere to alkyd or acrylic either, am I right?


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## DrakeB (Jun 6, 2011)

JourneymanBrian said:


> ok but calcimine doesnt really adhere to alkyd or acrylic either, am I right?


I'm quite sure it wouldn't to acrylic, not sure so much about alkyd. That's not normally a problem people have though, as far as I know, since very few people are interested in calcimine these days.


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## daArch (Mar 15, 2008)

A house we did back in the 70's/80's had calcimine on all wood work, previously painted woodwork. Although we never tested it, the age would indicate oil paint with lead. The calcimine was tenacious. 

It's probably the only time I saw calcimine on top of a previously painted surface, and definitely the only time I ever saw calcimine on wood trim.


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## DrakeB (Jun 6, 2011)

What did the trim ever do to deserve that?


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## JourneymanBrian (Mar 16, 2015)

Ok update: 

after multiple experiments my favorite version is this:

Put
4 volume parts of fat free cream cheese (same casein/fat content as fat free German quark)

in a bucket with 
1 part slaked lime

mix thoroughly, and let react at least 2-3 hours.

Soak 
10 parts of pigment powder
in very little water, mix to a thick paste, and let sit 30 min to absorb.

Mix this paste into the cheese/lime binder.

Add 4 parts boiled linseed oil to the combined mixture for added sheen and waterproofness. Stir thoroughly
(this step makes paint a tempera actually).

Paint can be painted over in a few hours, is wipable without chalking in about a day.

UV is said to continually harden the glue part of the mixture, the oil part dries faster than pure oil because its thinned but also because it is more dispersed and has more surface to oxidize.

you can go over the finish later with pure BLO or 85/15 BLO/wax for added waterproofing.

You get a high gloss after 2-3 coats BLO, depending on substrate

Thickened Stand oil (prepolymerized BLO ) can also be usef for the final clear coat.

Btw the clear coat also affixes any pigments that may still have chalked.

e.g.:

Board I painted with the recipe above, then waxed with 85/15 BLO/beeswax (cooled down to a paste). I polished with a cotton cloth after it had hardened a few hours.



















I primed with 50/50 BLO/ aliphatic thinner. I've read that 50/50 cheeselime binder/water also does the trick.


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## VictoriaLineberger (Dec 15, 2020)

daArch said:


> Although all these calcimine, casein, milk, blood paints have great properties, they become a nightmare when someone in the future wants to apply a modern day oil or latex paint on that surface.
> 
> The calcimine/casein paints were great on RAW plaster ceilings because they were dead flat, filled (actually HEALED) cracks, leveled real well, and easily maintained.
> 
> ...


I am unfortunately one of those homeowners who hired painters to paint my home before we moved in to find out our ceilings were never painted except for the Limewash after it was built. Now all of our ceilings are failing and look like crap. Do you have any advice on 1. How to remove the latex from the ceiling 2. How to tell if we have a pure Limewash, a casein, or distemper paint? It kind of gives off a blue hue in indirect light but shines white in direct sun.


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## finishesbykevyn (Apr 14, 2010)

VictoriaLineberger said:


> I am unfortunately one of those homeowners who hired painters to paint my home before we moved in to find out our ceilings were never painted except for the Limewash after it was built. Now all of our ceilings are failing and look like crap. Do you have any advice on 1. How to remove the latex from the ceiling 2. How to tell if we have a pure Limewash, a casein, or distemper paint? It kind of gives off a blue hue in indirect light but shines white in direct sun.


 Hmm. I thought it was a clients house, not your own house.. Story changed?


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