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.
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 |
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)?
ReplyDeleteooooh, 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:
Deletearticle 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.
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
ReplyDeleteHi 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.
DeleteBefore I discovered wheat paste, I used wallpaper paste - it's not totally natural but it's basically starch with a fungicide so it doesn't go off. It's quite effective mixed with clay or lime - a nice lustre and no dust. I never could decide if this was a good or a bad thing to use.... any thoughts?
DeleteHi Sigi,
ReplyDeleteI 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
#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!
DeleteThis comment has been removed by the author.
DeleteThank 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.
DeleteHi 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!
ReplyDeleteAll the best
Ruurdtje and Paul, the Netherlands
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?
Deletethanks 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.
DeleteThanks again,
Ruurdtje and Paul
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.
DeleteWhat can I use for a pigment for antique white?
ReplyDeleteyou can use white clay, like a kaolin. Purchase dry from a pottery supplier.
DeleteTried 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?
ReplyDeletewhat kind of sand did you use?
Deletein 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.
ReplyDeletethe 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.
Deleteprobably 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......
ReplyDeleteI'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?
DeleteHello! 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!
ReplyDeleteHi 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.)
DeleteHi Sigi,
ReplyDeleteCould 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
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.
ReplyDeleteHi 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.
ReplyDeleteOlly
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!
DeleteThanks 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
DeleteSorry, 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.
DeleteThank you so much, Sigi! We'll let you know how it all went. best wishes, Olly
DeleteHi Sigi,
ReplyDeleteThanks 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.
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.
DeleteI 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.
DeleteThe 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.
DeleteThank 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!!
DeleteWell, that's incentive to write more articles if there ever was one! :) Looking forward to seeing the fruits of your labor.
DeleteGreat 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....:)))
ReplyDeleteAh, 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:
Delete1. 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.
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.
DeleteHi,
ReplyDeleteIs 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
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.
DeleteThanks 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 ?
DeleteI 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.
DeleteThanks again Sigi
DeleteHi Sigi,
DeleteIf 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
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?
ReplyDeleteI 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.
DeleteHi 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?
ReplyDeleteThanks for any help!!
Clare
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?
ReplyDeleteThanks for any help!!
Clare
Hi Clare,
DeleteSo 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.
Hi Sigi,
ReplyDeleteGreetings 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
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
ReplyDeleteI recommend the following book to help you: https://www.amazon.com/dp/0857842692/ref=nosim?tag=downtoeartdes-20&linkCode=sb1&camp=212353&creative=380549
DeleteHi There-
ReplyDeleteWe 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!
oh that would be very sad indeed. what's wrong with the clay paint?
DeleteShe 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!
DeleteIf 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. :)
DeleteHi Sigi, Thank you for the very useful information. I would like to ask if there are any additives that work well with the clay paint recipe
ReplyDeleteyes, there are many additives that work in clay paint. It depends what you are trying to achieve and also what you have available to you
DeleteHello from Crete Greece!
ReplyDeleteWe are currently finishing off clay walls with a 5mm (0.2inches) thick layer of kaolin clay.
Have read that KAOLIN cause of its structure cannot store humidity. So I wonder to what extent it delays the humidity to pass through to the clay plaster behind, that acts as the humidity regulator for a space.
We use a mix of 1:2 kaolin and quartz.
Our other concern is with the WHEAT PASTE. How diffusion open is it and does it also deprive the clay plaster its wonderful property as a humidity regulator?
We intend to use 1kaolin to 1/4th wheat paste as with samples it was enough to avoid dusting off (Is it too little wheat paste?)
We have been living in the house a whole winter with perfectly regulated humidity from the clay plastered walls, and do not want to loose the wonderful atmosphere!!
Sigi, thank you for sharing your precious knowledge in such an easy to understand way, its a talent!
So you are describing a plaster finish, not a paint. So I would not use this recipe here on this page. Rather, I would use this: http://buildnaturally.blogspot.com/2012/08/finish-clay-plaster-recipe-wall.html
DeleteIf you apply thick using the above recipe, you will likely get lots of cracking.
For humidity control, kaolin works fine, as does wheat paste (if you make it yourself)...so no worries from that standpoint.
Hi Sigi - We have clay plaster over straw bale walls that our young children have really marked up and dented in the short time we've lived here. I'm wondering if there is a paint or natural finish I can put over the plaster in the high traffic areas that might strengthen the wall surface and increase its scratch-resistance. Any advice is much appreciated!
ReplyDeleteIt's hard to say exactly what is compatible with your clay plaster, without knowing what ingredients were in the plaster and what finishes may have been applied already. That said, I would try a hardening oil, such as linseed or tung oil. These oils harden over time with exposure to oxygen, creating a polymer integral in the surface of the plaster that effectively hardens/densifies the surface. I would definitely do a test area before you commit to your whole wall. Also, know that the hardening reaction takes about 2 weeks at average ambient temperatures (longer if it's cool), and then it keeps hardening somewhat over time. Hope that helps!
DeleteHi I have made a clay paint going over a clay wheat past, sand and cat tail fluff plaster over drywall which was primed with wheat past and sand. It is a very finish with no dusting would i need to wet the wall before paint with clay paint. I am applying the paint with an airless paint sprayer?
ReplyDeletethank you
Henry Wiersma
HI Sigi
ReplyDeleteI am mixing up a clay plaster/ clay alis for final layer of our earth floor. So far I have mixed up about 1:1:4 lime: clay:sand.. its a sloppy wet mix. Will be adding some horse poo instead of chopped straw) Would you also include wheat paste for floor plastering? I will eventually oil and wax floor, but meanwhile we are living in house already and need it not to be dusty.
The present floor surface is hard and smooth but quite sandy/ dusty..I didn't manage to burnish all over before it dried. it has lime and a high sand content to clay based on a tataki recipe, packed over the prior layer of cob which had dried with big cracks.
I would recommend to do tests of any recipes you use. There are so many different types of clay that it's difficult to give specific recipe advice without touching and working with your particular clay. Here are some general recommendations:
Delete1. make sure all of those big cracks are filled & repaired before moving forward. Otherwise you will have cracks develop in the layer(s) above.
2. be careful mixing lime and clay...definitely do tests!! There are minerals in the clay that can effect how the lime cures and can cause the resulting plaster/alis to sort-of coagulate and not be strong (particularly for a floor)
3. horse manure is a great source for chopped fiber
4. make sure your sand is very angular/sharp. If you are doing thin layers, also make sure it is fine in size
5. I never add wheat paste to a floor because I know it will get oil, and the oil creates hardness and stability (which is also what the wheat paste can do in certain plasters). Sometimes when you oil a clay finish with wheat paste, you will get a blotchy finish. So best to leave it out, and work on getting your clay/sand proportions just right.
6. don't forget to rework your floor as it is drying. You can do this several times. The more you work the surface, the tighter the clay bonds become and the stronger your floor surface will be.
Hope this helps.
Hi Sigi!! My name is Andrea from Mexico :)
ReplyDeleteThanks for the information!! I was commissioned to paint a mural and i was planning to apply the clay paint to an MDF board (We can´t touch the walls) and over the clay paint the mural with vinyl paint. Do you think it´ll work?? Is there something I can add to avoid molding?
Thank you!!
hmmm...so first question is whether the mural is inside or outside. Also, know that if the MDF expands & contracts (usually with humidity), it will crack the paint. How long do you need the mural to last? I would avoid anything vinyl period. It has an ecological impact in every single part of it's life-cycle as a material, especially during manufacturing.
Deleteps. clay paint doesn't mold
DeleteDear Sigi!
ReplyDeleteI plastered a brick masonry stove with (multilayer) plaster.
The final layer was to be black.
I found the graiest clay I could.
And tried to obtain the black color by addition of Fe3O4.
The oxide addition was 5% of dry weight of the mix.
The sample after curing were OK and did not tint a palm while dry touching.
After the application and drying of the last layer (of such composition) to the whole stove surface it gives of the color when you touch it.
I'm a bit down.
Any ideas what could go wrong.
I can find neither occasional nor systematic error in the preparation and application process.
BTW. seems I'm an old timer. I stil preffer to ask in here than on ur facebook fanpage
Handshakes
Oh gosh, it's really challenging to problem-solve over the internet. Nothing stands out in terms of what you used or how much. And weird that your test sample worked fine. It sounds like for some reason your binder is not encapsulating the pigment. (I assume you've let the clay plaster dry completely?) You might try sealing the surface. That would at least address the issue. You can use a hardening oil (my favorite is hemp oil) or you can use a wax finish. sorry you had this frustrating experience!
Deletehello Sigi,
ReplyDeleteI am an architect from India and had tried making clay paint as per your recipe.But our climate is extremely humid and i started seeing fungus appear on the paint and wall.i think it may be due to the wheat. any suggestions as to what i could do to tackle this?
Do some testing as follows. You could first try just the clay and sand, and make sure you burnish or sponge. This may crack, however, depending how much you compress the surface. If this cracks you can try fermenting/soaking clay with cow dung, then screening through a sieve to remove the larger pieces, and adding the sand. Or cactus juice also can work; here we use prickly pear cactus, but I'm not sure what you have in your region. You can also try mixing 1 egg and 0.1 liter vegetable oil for every 3 liters of clay/sand combination. Not sure if the eggs will have the same problem in your humidity. Really what you are trying to add is something sticky but that does not shrink when it dries. This improves the hardness and eliminates dusting in the clay paint
DeleteI can't speak to use on canvas, as I always use these paints on walls in buildings. I will say that on walls the paints are extremely durable (unless otherwise noted in the recipe)
ReplyDeleteHi Sigi, thanks for all the great info! If I intentionally wanted a crackly surface, do you think it would work to reduce or eliminate the amount of sand? Will that cause poor adhesion / it to flake off the wall?
ReplyDeletegosh, I can't say for sure as I have not tried it. But my guess is that it will crumble from the wall slowly over time. Maybe you can do a test sample and see
DeleteThis is brilliant, thank you! Is the clay essential, could you not just use pigment and wheat paste?
ReplyDeleteyou could, but it wouldn't be opaque and it wouldn't help to regulate humidity...which clay will help do
DeleteThis is such an incredible resource, I can't thank you enough! I was wondering if you'd have any recommendations for how many coats of paint to use of this recipe over drywall/gypsum plaster, or existing paint? I have limited pigment, so don't want to run out and wondering if I should do a white undercoat first with a cheaper pigment, then use the more expensive coloured pigment just in the second coat?
ReplyDelete