Friday, October 14, 2016

Benchless School Box Build - Part VI - Home Made Milk Paint

Milk-painted box.

I think milk paint is a neat finish, and I wanted to use it for my school box. I've used milk paint before, but I have only ever used the pre-mixed stuff that is mixed with water.

Milk paint like that is much more common (and affordable) in the US than it is here in Europe, so I thought I would give a try at making my own.

Most of the milk paint recipes online have as an ingredient hydrated lime, or some such thing. I didn't really have immediate access to that, so I looked for a recipe that only had things I could get at the grocery store, or the home center next door.

I came up with a recipe from Martha Stewart.

Really.

I thought it looked easy enough, so I gave it a shot.

All I did was take a half liter of room-temperature skim milk, and I squirted a healthy squirt of white wine vinegar because that's all we had.

It immediately began to curdle, so I lightly covered it and set it aside for two days.
Giving it a try.
Maybe now would be a good time to discuss how to do this in the kitchen without risking the death penalty from the Frau.

Take my advice and don't use good kitchen bowls, mixers, utensils, etc. for your first milk paint project, find some old junkie containers or buy some cheap ones from the Chinese flea market.

Just sayin'.

You were warned.

After a couple days, there is a good bit of curd and the liquid stuff (whey) is much clearer.
After two days.
Here is where I ran into some problems with Martha Stewart's recipe.

In Martha Stewart's defense, two other similar recipes I found had the same defect. It doesn't really describe which part you should save and which part you should use after straining the curd from the whey.

Needless to say, I did it wrong. I threw the curd out, and mixed some coloring agent with the whey.

It seemed reasonable to me. There is no way that nasty, cottage cheese looking stuff could ever make paint. It's too thick.

I was wrong.

It took me a while to figure out, I tried a couple things with my colored whey, including adding baking soda. What a mess! I'm glad I tried painting it with a test piece.

Eventually, I ran into this old blog post written by Brian Anderson for Lost Art Press. I couldn't envision it when I first read this post, but now that I knew what he was talking about, it was easy.

Just make up some more curds, add tint and whip them up until smooth and creamy.

That's it. Honest!

To make curds faster, heat up the milk until just before boiling, then add the vinegar and turn the heat off. 15 or 20 minutes later, there should be some curds to use, although there will be more if you wait longer.

I didn't get many pictures of the whole process. I'll just describe what I did instead.

I strained the mixture to get the curds by themselves, and let the whey drain down the sink. I used a big metal colander, and lined it with an old dishrag, since I didn't have any cheese cloth.

Then, I made sure to rinse the curd the best I could. The LAP blog entry suggested doing it two or three times. I'm not sure how he did that, probably had better drainage. I did the best I could. I think the idea is to remove as much acid from the vinegar as possible.

This leaves a clumpy glop of white goo, about the consistency of wet sand. The first batch I did, I put in a big mixing bowl, added a bunch of tint, and mixed with a fork and a whisk.

By the way, all I used for the green tint was some of the paint tint from the home center. It is the stuff that is used to color white house-paint whatever color you want. I found some that was water soluble, and went with that. Next time I might try a more traditional (read, "cheaper") tint such as brick dust, charcoal, or curry. For now, I used what I had.


What I used to tint my milk paint.

Mixing the cottage cheese mix this way makes an awful mess, and takes forever. After about thirty minutes of mixing this little bit of paint by hand, the mixture was about the consistency of mom's gravy.

Clumps and all.

Now I had something that I could use that vaguely resembled paint that I could apply with a brush.

My previous experiences with powdered milk paint that was pre-made resulted in a finish that was almost chalky, opaque, and very dry looking. This milk paint was nothing like that.

I was expecting it to have some of the crumbly bits on the surface that could be brushed off with your hand when it dried.

This mixture was very hard when dry, and almost glossy.  I ran out of paint after three coats, and this is where I was.
Three coats.
It was also a bit translucent.
It is really clear. BTW, that is my mixing bowl in the corner. I got in huge trouble because the green tint didn't come out.
While this is an interesting look (the Frau says "interesting" is the little brother of "Scheisse"), I wanted something a bit more traditional. Also, there were some defects in my painting job such as ugly brush marks that wouldn't wipe off like I thought they would.

The next day I took some 180 sand paper and smoothed the whole thing down. I wound up getting to bare wood in a couple spots. My first plan was to smooth it out and darken it up with boiled linseed oil.

The more I thought about it, the more I decided BLO probably wouldn't fix all my problems. This paint is kind of glossy, and I suspect BLO might not penetrate like it does on the milk paint I've tried before.

The answer was to make another batch of paint. This time I took the Frau's electric hand mixer and smoothed out the curds in no time flat. I thought I was being smart and did this before mixing the tint. This would have worked if I didn't put a big green thumb print on it when I put the business end in the dishwasher.

While this time the mixture was creamy smooth, it seemed a bit too thick. I thinned it with a little water, and that worked great.

If you thin it with water and think you might have overdone it, just put your mixture in the fridge for 15 minutes and it will thicken up a bit.

I applied three more coats, this time using my best brush-stroking technique, trying to leave as small of brush strokes as possible.
I think it turned out much better.
I like that the dovetails and other joinery details can still clearly be seen.
Crisp chamfer is still visible.

Close-up of a dovetail pin.
I really like this finish. Now that I kind of have it figured out, I think I can experiment with it a bit more. My guess is that adding some lime or one of the other recommended additives will make the paint a bit more chalky and opaque. There is definitely some experimenting to do.

This paint is almost glossy, and very tough to the touch. I had originally planned on topping this with BLO, but I think I will not. If anything, perhaps a coat or two of paste wax.

Next up, the completed Benchless School Box and AAR!

16 comments:

  1. That is very interesting. I went to buy some liquid milk paint here in the US and was told that it must be coated with varnish to be durable, but it seems like yours doesn't need to be. I think hydrated lime is readily available here.

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    1. Hi Andy,

      I bet there is something readily available here, too. I just was too lazy to figure out what it was and where to get it.

      This finish indeed feels much different than what I know as milk paint from the US.

      Cheers!

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  2. I like the way it turned out. and agree with the Frau that the first one is "interesting"

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    1. It's always good to agree with the Frau.

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  3. I like the look of this milk paint. I like the mix-your-own stuff that I get here in the states, but it is a lot of work to get a final finish. I usually burnish the painted piece with 0000 steel wool and then three or four coats of shellac. Then rub that out with steel wool and finally a couple of coats of wax. Your stuff looks great straight from the brush. Very nice!
    Using management's cookware is strictly OFF LIMITS and comes with harsh penalties...when I get caught. ;)

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    1. Hi Greg, thanks for the comment. I've never done that much work for a finish. I would probably try something else, first.

      I'm amazed that such a simple thing turned out. I think I'll just mix up some 50/50 beeswax and turpentine, and use a coat or two if that.

      Cheers!

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  4. I've found that apple juice works well too. The last time I did it was black over a crimson oil painted finish that didn't turn out. I'd put a layer of dewaxed shellac over the oil paint and then the milk paint,...after a few months it turned into a really beautiful alligator craze effect.

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    1. Hi Paul,

      Neat idea. Lemon juice is also supposed to work. I think the idea is to use something acidic, whatever you have, and that will create curdles.

      Cheers!

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  5. Brian Anderson here - I've seen a couple of references to my blog on milk paint. Since people seem to be interested, if there is a point or two that need clarification, let me know - it would take two minutes to go back and edit the blog.

    To rinse the curds, you just run water through them, and then gather up the corners of your cloth and squeeze the liquid out. You end up with a pretty thick paint, but it brushes out no problem and ends up pretty opaque. Also adding slaked lime or whatever makes it more opaque. Here in France if you look in the part of the hardware store where they sell cement and lime and whatnot, they sell jars of pigments to tint cement renders and limewashes. Like 10€ for a pint jar that you could paint your house with.

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    1. Hi Brian,

      Wow,thanks for the comment.

      Your post was great. It cleared up some things for me. I'll definitely be doing some experimenting with milk paint.

      Cheers!

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  6. Hi Brian

    I have also been making my own milk paint. I have not been using slaked lime though. I found a danish recipe that used ammonium bicarbonate to dissolve the curds. That works very well, even though it makes the paint smell like ammonia (until it dries).

    Recently I found another traditional Danish recipe for milk paint that is a lot more simple. Just mix buttermilk with slaked lime and ammonium bicarbonate. Let it sit for a coulpe of hours and stir in the pigment.

    Organic buttermilk is best because it contains more protien and because it has not been homogenised.

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    1. Hi Mikkel, thanks for the comment! I might try that recipe with bicarbonate of soda.

      I like the idea of buttermilk. It is a nice, paint-like consistency already.

      There are so many nice recipes for paint out there. One is a beer paint. It specifies to use a dark beer, though. I couldn't imagine wasting it that way. Maybe it would still work if I "ran it through" once, first. Cheers!

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  7. Maybe you should clear that one with the Frau first... ;-)

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    1. Haha!

      Seriously, I've discovered that most of my ideas get vetoed after I run them by the Frau. I feel like I get a lot more done if I just do it and show her the finished product.

      Usually, she's right, though.

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