Recipe for natural, non-toxic paint from clay
Thanks to Sigi Koko of Build Naturally.
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.)
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.
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