02 March 2013

Make Natural, Non-Toxic Paint from CLAY!


The particles of clay are like mini suction cups, which makes clay a superb sticky binder!  Sticky binder, means you have a great way to put pigment (paint) on a wall.  And it's completely natural & non-toxic.

This clay paint recipe can be made from finely sifted clay soil or powdered potter's clay.  If you use clay soil, test it first to determine the proportions of clay to sand, and adjust the recipe below accordingly.  You can watch our video on how to test your soil for clay content on youtube:


This clay paint recipe has an additional binder that helps prevent the paint from being dusty once it dries...that is, wheat paste...which is made simply by boiling flour & water.  Wheat paste can also be used as a glue.  (When we were kids, we used it for a variety of projects, from paper mâché to installing wallpaper.)


Alis/Clay Paint
thick, opaque finish for absorbent wall surfaces; ideal over clay plasters or smooth cob
1 gallon water
4 quarts powdered clay
2 quarts fine sand
1 quart wheat paste (see recipe below)
Pigment, whiting, mica, or chopped straw, as desired
Mix all ingredients together thoroughly, with a large whisk or a paint mixer attachment on a drill (or similar).  Final consistency should be between heavy cream (before it is whipped) and yogurt.  Apply thickly with a good bristle brush.  When leather hard (slightly firm), smooth the surface by buffing with a damp tile sponge.  Rinse the sponge frequently.  Optional final surface treatment: buff with a very flexible Japanese trowel or polished stone, or buff with a dry cloth.
Covers approx. 150 SF

Note on color: you can choose a clay that is the color you want your paint to be...ie, a rusty orange clay will make rusty orange paint.  Or you can use a white base clay and add any natural pigment to achieve any variety of colors, from earthy shades to vibrant colors.  I use pigments from  www.earthpigments.com or www.bioshieldpaint.com.


Wheat Paste
binder added to clay paint
Bring 1 quart water to boil in a non-aluminum pot.  Meanwhile, mix 1 cup flour with 1 cup cold water until smooth and lump free.  (If you can’t get it lump free, run through a strainer.)  When water in pot is boiling, slowly add in flour/water mixture, stirring constantly.  Bring back to almost a boil, stirring constantly, until mixture thickens.  Remove from heat and allow to cool completely.  The top will get a skin on it as it cools.  You can prevent that by stirring as the mixture cools, or by putting a piece of plastic wrap against the surface as it cools.  Or simply peel the skin off before using the wheat paste.  Make wheat paste within a day or two of when you will use it.  It will go rancid after a few days (faster in warm weather), and then is not usable.
Makes approx. 5 cups of wheat paste


Resources
For more general information about natural paints, and links to other natural paint recipes, see our previous blog post: Paint it Green!...with natural paints

I included this book in my last post, but it really is by far my favorite book on natural paint.  The format resembles a cookbook...recipes on one side and a photo of what the paint looks like on the other.  This book contains tons of information and inspiration.
click cover for more info or to purchase

56 comments:

  1. wonderful info, thanks Sigi. I've got plenty to research. Are any of these paints especially good for covering old plastic paints (on plasterboard - which 95% of Australian homes are lined with)?

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    1. ooooh, great question, but unfortunately, natural paints do not like slick, plastic surfaces. Natural paints mostly adhere best to porous surfaces, and plasticizers are inherently non-porous. That said, you can coat the latex (or similar) paint with a primer that is compatible with your natural paint...kindof an intermediary. You would want to do test areas to be sure you have compatibility with your particular substrate (existing surface) as well as with your intended natural paint. Here are a couple resources to check out:
      article on exactly this topic: http://www.earthpigments.com/coating-existing-latex-paint.cfm
      Another article specific to casein (Milk) paint that recommends Zinzer Bullseye Primer Sealer as a primer:
      http://www.richesonart.com/products/paints/richesoncasein/richcaseinfaq.html
      Hope this helps! Let me know how it goes if you try an experiment.

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  2. Is there anything you can use other that the wheat paste? I want to start making paint for my shop to sell in small quantities. This is so much work for such a small amount. Plus I need something that will last in the can. Any other ideas or can you point me in a direction of a resource? Thanks, Michelle

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    1. Hi Michelle, That's a great question. I have never seen a recipe that didn't use wheat paste or some other starch. That ingredient improves the adhesion of the clay to your painted surface and it helps prevent dusting once your paint dries. I did a little bit of research and also came up empty for recipes that don't have some type of starch. Perhaps you could experiment by just eliminating the wheat paste from the recipe and painting it on a dampened, absorbent surface. If it sticks, your paint is fine. If it dusts, you can seal the surface after-the-fact with linseed oil, wax, or clear milk paint. Hope this helps! Sorry I don't have a direct answer.

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  3. Hi Sigi,
    I have used a slightly different recipe, which was very much the same as yours (1 part clay, 1/2 part wheat paste, and 2 parts water - no sand - and I used 2.5 parts lime instead of pigment to colour) - i loved making it and applying it over a lime/hemp wall, very easy to use! However, the second layer, which I made a little thicker than the first, has started to crack in places, & is coming away from the first layer. Would you be able to advise me on how to fix it? Should I try to take this layer off and re-apply? Should I apply a third layer? Or, do you have any other solutions? Many thanks! Monique

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    1. #1 cause of cracking clay plaster is not adding enough sand. So that is the highest probability of what went wrong. #2 cause is not wetting down an absorbent substrate before applying the plaster. #3 cause is uneven drying or drying too quickly. So I can't really advise you on what your particular problem is, but those are the top 3 issues. in terms of repair, it is not really possible to reconstitute a clay plaster that has wheat paste in it. (Otherwise you could possible dampen the surface over a period of days and rework the surface with a sponge or trowel...but no guarantees that would work even without the wheat paste.) Personally, I would remove the cracked plaster and start over with a mixture that has adequate sand in it. I would also be sure to adequately soak your base plaster prior to applying the new mixture. Hope this helps you!

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    3. Thank you so much! I have read other parts of your website and am much more informed! I think I know the problem. I will go with your advice and start again with sand in the mix. Thanks you once again.

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  4. Hi Sigi, thank you so much for this treasure trove of info on natural building! We're about to make our own earthen floor in our earthship-inspired home (see www.aardehuis.nl/en/ ) and wonder about the durability of the clay paint you discribe above. In other words, does the paint layer itself need a finishing layer on top of it with sealing stuff like lineseed oil? We hope you can help us out!
    All the best
    Ruurdtje and Paul, the Netherlands

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    1. This clay paint is dust-free, and pretty durable unless you need to scrub/clean the walls a lot. If it's in an area you know you will want to clean the walls regularly, then I would skip the wheat paste and put one to two coats of linseed oil instead. Does that help?

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    2. thanks for your quick reply. One other question came up: can you give us an estimation of how long it will take the floor to dry out entirely? We want to do the floor this summer and the average Dutch temperature in summer is approx. 72 F.
      Thanks again,
      Ruurdtje and Paul

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    3. drying time depends on temperature, humidity, and air flow. With decent airflow, warm weather, and low humidity, you can estimate about 1-1/2 weeks per inch of thickness (so a 4" floor takes approximately 6 weeks to dry out. But really this is difficult to estimate, especially from afar.

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  5. What can I use for a pigment for antique white?

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    1. you can use white clay, like a kaolin. Purchase dry from a pottery supplier.

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  6. Tried this on drywall prepped with your sanded primer recipe and had some bad cracking flaking of the clay paint and wheat paster primer from the drywall. Not everywhere but some areas are chipping badly. Any suggestions?

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  7. in the clay paint i used super fine silica sand from pottery store. In the sanded primer a bit coarser, it was fine sand from home depot for making concrete mortar that i ran through a sifter to get any tiny stones out.

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    1. the sand on the wall needs to be coarse, so you have some grit on the wall. You should see/feel the texture when your done applying the primer and it has dried.

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  8. probably just going to sponge it down and go at the wall with a floor scraper to bring it back to drywall. not sure after that. i really was hoping it would work, i dont want to use any chemical paint. perhaps i will just try store bought milk paint......

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    1. I've never had the issue you are describing, so it is difficult to problem solve without knowing all the variable. I always recommend doing a small bit first, for this reason, so you can "test drive" the new material before committing to a larger area. It's possible the sand in the alis was too fine. It's possible that it was applied to thickly. There are a lot of variables! If it's not bonding to the wall, then the issue is likely the primer. Which can be an issue with the wall itself (like if the wall has oil spots on it, then the primer can't bond). If the problem is in the paint itself, then there is an application or recipe issue with the alis. Can you tell where the origination point is?

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  9. Hello! Ive tried your recipe, but on a smaller scale. I omitted the sand, and it seems that the clay paint does not seem to stick well to the surface, it comes off and cracks easily. How do i make it durable and waterproof? Thank you!

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    1. Hi there, so you can't omit the sand...that's what keeps it from cracking. As for why it is coming off, that likely has to do with the surface preparation. You need something clean (oil free), non-slick (ie, not over latex paint or similar), and a bit absorbent. It should be durable as is. Clay paint can't really be made waterproof. But it can be made water-resistant by using a hardening oil on the surface after it dries (like linseed oil, tung oil, etc.)

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  10. Hi Sigi,
    Could you please advise us? We have lime/hemp walls and would like to paint them with a nice earthy colour. We looked at lime wash but you only really get pastel shades if you are applying it on dry lime plaster. Would the clay paint recipe work on lime plaster? many thanks,
    Olly

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  11. As long as there is nothing sealing the hemp lime, yes, you can use a clay paint. Just be sure to dampen the walls before you apply the paint. But also you can get fairly saturated colors with lime wash. Definitely do some test areas to get your mix and technique down before you commit to a whole room/wall.

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  12. Hi Sigi, Thank you so much for your advice. We have just one other question and it is this: can you use naturally damp clays? We live in central Portugal and it's a bit difficult sourcing some products. We went to a local pottery the other day to see whether they used clay powder but they just had large slabs of moist grey clay. We know we can get some really beautiful reddish clay from a clay pit just south of here, which they use to make the distinctive red tiles, but it will most likely to be damp as well. thanks again for your advice.
    Olly

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    1. Hi Olly, yes, absolutely, you can use wet clay. I would use soil instead of wet bagged clay from the pottery supplier. The soil will be easier to work into a plaster and probably already has a bit of sand in it. What you'll need to do is some test plasters with various percentages of clay soil and sand, to find the one that is the strongest without cracking or dusting. If it cracks, it needs either sand or chopped fiber (or both). If it's dusty, it's not enough clay. Have fun!

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    2. Thanks Sigi! This is very helpful indeed however I just want to be clear that we are only talking about clay paint not plaster i.e. we would like to work up the damp clay into a paint mixture following your recipe above. We already have lime/hemp plaster on the walls. Thanks again! Olly

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    3. Sorry, yes, I was answering for plaster. Luckily, the same things are true. :) Make some tests to get your proportions correct. If the paint cracks a lot, it needs more sand. If it's dusty, it needs more clay. And be sure always to work on a damp surface.

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    4. Thank you so much, Sigi! We'll let you know how it all went. best wishes, Olly

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  13. Hi Sigi,
    Thanks for a great article. I was wondering, if I did a colored limewash: Primer Coat, Wash Coat, then Patina Coat ...could I use wheat paste as an additive in both the wash and patina coats? Thank you for any suggestions.

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    1. I have never used wheat paste as an additive in any lime-based paints, nor have I run across any recipes for limewash with wheat paste. So I can't make any recommendations one way or the other. What are you trying to achieve with the wheat paste? For sure I would do tests before you commit to the whole wall.

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    2. I am thinking I need to add an additive for adhesion and to cut down on future dusting of the wall. Saw the recipe for the limewash here: http://www.earthpigments.com/limewash/ ...They use an Acrylic Binder to enhance the adhesion of limewash. I can't help but think the Acrylic Binder would deter the wall from breathing. Yes, will do a test before committing to the entire (interior) wall. Thanks.

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    3. The lime itself is the binder. But you have to make sure that it is truly calcium hydroxide, and I would make it from a nice fatty putty. Poor lime = poor binder = poor adhesion. But good lime = great adhesion and no additives necessary.

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    4. Thank you so very much; so much information out there - but I seem to always turn to your blog/advice! I promise to send a photo once I get at least one wall done!!

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    5. Well, that's incentive to write more articles if there ever was one! :) Looking forward to seeing the fruits of your labor.

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  14. Great stuff! Maybe you know a trick for applying clay to canvas? I am trying to achieve a cuneiform effect on parts of my painting, and will use a stylus to write with. I have tried joint compound but that does give great texture, but the letters etching doesn't hold. Clay would be ideal....:)))

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    1. Ah, that's a tricky one...when the clay is wet, it's very sticky and you can easily bind it to anything. The challenge begins when the clay dries...and becomes very very brittle. Here are some ideas you could try though:
      1. mix the clay with wax paste
      2. add fiber to the clay (like chopped straw, cattail fiber, paper pulp, etc.)
      3. add wheat paste to the clay (flour boiled in water)

      Those are the first ideas that come to mind. Let me know what you end up trying.

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    2. Also, it will help if you have texture on the canvas for the clay to key into...even just the texture of raw canvas is helpful. Or put gritty sand in your gesso.

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  15. Hi,

    Is this clay paint recipe water resistant ? I plan to paint it for classrooms but sometime the wall need to be cleaned by scrubbing with soap and water because of a scratch dirty ( from pen and pencil).

    If it is not water resistant, how to solve this issue ?

    Pleas suggest.

    Thanks

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    1. I wouldn't call clay paint scrubbable. You can tighten the finish by polishing the surface and then seal it with a wax paste, and that makes it wipeable with a damp cloth. But not really scrubbable. (The distinction to me is that scrubbing would use something abbrasive.) You might make yourself a little sample, let it dry, seal it with wax paste, and then see if the finish is durable enough for your classrooms.

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    2. Thanks Sigi for your suggestion. One more question, regarding a wax paste, is it good to use the bee wax or soy wax ? If not,which wax paste do you recommend ?

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    3. I actually purchase a wax paste. My favorite is Roman brand. I believe theirs uses beeswax. I know it is possible to make your own, I just don't have direct experience with that and wouldn't want to give you advice that isn't based on experience.

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    4. Hi Sigi,

      If I polish plaster or lime paint with roman beeswax as your suggestion, suppose 3 years later I want to repaint the wall, what is the application ?
      Do I need to remove or wash off the old paint and wax ?

      Thanks

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  16. Hi, Sigi, my name is Peter, writing from Estonia, Europe. I have on my land nice reddish clay but ...We have a bit awkward local custom here - we walk on the floor on socks or bear foot, no shoes on, just like Japanese do. That creates a new issue here what bothers me is that if you do adobe clay floor, how do you clean it afterwards? clay paint is not waterproof, does oiling or wax solve problem so you could wash floor. Tung oil would be interesting but can regularly water floors? Or you do have some other suggestions?

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    1. I never wear shoes in the house either :) The clay floor is almost always sealed. The 2 most common sealers are hardening oil (such as tung oil, linseed oil, hemp oil, etc.) or beeswax paste. You can even use hardening oil and then top it with the beeswax. The oils soak in and become integral with the adobe. The beeswax soaks in a bit but wears over time and will need to be reapplied. Both finishes are easily washed, mopped, swept, etc. and both keep clay off your socks.

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  17. Hi Sigi, wow what an amazing resource you are. We built a cob house on the West Coast of Canada. We plastered the interior of our cob house last year with available materials. There are lots of cracks but nevertheless adhesion is good...It is dusty and crumbly around windows where there is more play. It's very fine and smooth. (ie: probably wouldn't take another layer of plaster well without more texture) We were thinking paint would be less work and take care of the dust with the addition of wheat paste...would you recommend also adding paper pulp for more strength?
    Thanks for any help!!
    Clare

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  18. Hi Sigi, wow what an amazing resource you are. We built a cob house on the West Coast of Canada. We plastered the interior of our cob house last year with available materials. There are lots of cracks but nevertheless adhesion is good...It is dusty and crumbly around windows where there is more play. It's very fine and smooth. (ie: probably wouldn't take another layer of plaster well without more texture) We were thinking paint would be less work and take care of the dust with the addition of wheat paste...would you recommend also adding paper pulp for more strength?
    Thanks for any help!!
    Clare

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    1. Hi Clare,
      So here's the thing...if your substrate is weak (crumbly, dusty, etc.), then a surface finish is going over something weak and therefore will also be prone to dusting, crumbling, etc etc. There isn't a paint or skin-type finish that I know of that will magically fix plaster that is sloughing off. You might (stress "might") be able to address the dusting issue with some kind of absorbent hardening oil (ie, that soaks into the surface and then cures to bind the surface dusting). But crumbling suggests plaster that doesn't have enough binder in it, and I don't know a way to fix that without drastic measures.

      If it were my house, I would first go around and remove anything loose. Then I would take a board with metal lath over it and rub it all over the wall to create texture. Then I would look for any cracked areas and patch those with strips of burlap or some other plastering tape to keep the cracks from telescoping in to the finish. Then I would dampen the wall really well and put a new thin (1/8") coat of finish plaster on. (And before I commit to a recipe, I would test the heck out of the finish plaster to be sure it will be strong and not dusty.) Then you can paint it if you like (or just keep the plaster as your finish).

      Hope that helps.

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  19. Hi Sigi,
    Greetings from Latvia! I would like to paint our kitchen's lime plastered walls with an alis paint, however, you know the kitchen is high traffic! I was considering some linseed oil coats after but I'm afraid it wont breath enough (it is on the northside of the house too, of standing log) and that along with all the moisture from the kitchen activities, like the pot of water always on the wood stove in winter. Do you think alis has a place there? or is linseed oil coating breathable enough??
    thanks for any suggestions and for you website,
    clare and edgars

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  20. My name is Lanre Adedokun from Nigeria. Am interested in making clay plaster and clay paint if my own and i need to know the best combination. Kindly help me

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    1. I recommend the following book to help you: https://www.amazon.com/dp/0857842692/ref=nosim?tag=downtoeartdes-20&linkCode=sb1&camp=212353&creative=380549

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  21. Hi There-
    We painted our home about 2.5 years ago with this same recipe of "earthpaint" and are no longer living there and getting ready to sell the house. Our real estate agent has suggested that we re-paint with a latex based paint and we are wondering if you have any experiencing painting over top of earth paint with latex based paint? We are not sure if we need to wash the walls, sand them, or if we can just paint right over top. Any experience with this? Thanks!

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    1. oh that would be very sad indeed. what's wrong with the clay paint?

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    2. She thinks that there are two many colors going on in the room and that the walls should just be painted one color. I suppose it may just be easier to mix up a batch of one solid earth paint color and re paint with that!

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    3. If you repaint, I would definitely use clay over clay (not latex). Or limit the other accent colors in the room so the walls speak for themselves. :)

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