Clay finishes on ply wood?

Hiya everyone,

Just looking into home made clay paint for my tiny home, I've got some new dry wall going up soon in the main bedroom and planning on using a conventional primer from Natural paint co. and then use the home made clay paint on top.

The rest of the tiny home is all ply wood (I would gib the whole house if I could but its a bit out of budget and time constraint) just wondering what experience people have with using clay paint on top of ply wood - does it need to be primed first with a timber primer? Our ply has got 2 coats of water-based urethane already so I was thinking that it might be ok to use the gib primer instead

What luck have people had with painting over ply wood and also with using the clay paint on drywall?

Thanks guys!

I am sure you can find others here with more credibility, I can only add my mediocre opinion

Not sure by what you mean by "gib", could you perhaps give details, please
Are you making the clay paint, if so then what are ingredients and proportions?  That is crucial. Plywood sounds like it's  in a tough category, any time I work with that I prime it , both sides and edges, to begin.  That is from a great uncle, his style.
You say it already has two coats of urethane on it..... and I would not attempt any further coats  before sanding it all.  Otherwise, your next coat will eventually slide  off or leave a funky finish.  Painting on raw wood is much easier, and efficacious, than painting over sealed wood. Can you be specific about the two coats you used for that plywood? Tread , and good luck.

Hi Rico, another word for 'gib' is plaster board if that helps. Clay paint mixture would just be standard clay/sand/wheat/water to make it a medium to thin mixture.
The ply has got 2 coats of urethane and they are really thin and still is quite rough wood, not sure much else about it as we didn't put the coats on. Hope that helps.
I'm thinking if I do a light sand and then prime it it should be fine to paint over - possibly

I can not imagine that putting a clay/sand paint on wood would have any durability especially if put on a layer of plastic. I would suggest to take a raw piece of plywood and then try it on an area at least 3x3', as smaller areas may give false impression of success. Only then, after making sure that it works, it would make sense to work on all surfaces.
May I ask why to try to apply clay paint on wood?

Hey! I just posted a similar response on this page. I made a clay paint with linseed oil and natural pigment, mixed up, and applied directly to sanded plywood with no primer. I did 2 coats, and sanded in between as well. It's held up for a year and a half (so far) with heavy wear and tear from being a camper van that I was living in full time (dogs, chickens, people, bikes - constantly moving in and out)

The mix with clay worked pretty well for me, but I ended up just mixing the pigment and linseed oil to create a paint in subsequent projects. Its still non-toxic, and a little easier to work with in my experience.

That blue looks good.
Is you ceiling a bamboo blind help up somehow?

Thanks everyone for your insight!

@Cristobal, yes very true I see what you mean - I didn't think about the fact that it might not stick as well to the varnished ply, we're going to try a test spot this weekend and see what happens! We're wanting to paint a couple walls of ply just as to add some colour as the whole house is ply interior at the moment and to possibly help seal off some of the off-gassing (if we were to use a conventional primer)

@S Ritter, awesome thanks for that I'll keep that mixture in mind and give it a try, the blue looks great :)

From my experience clay will stick to most anything solid, that isn't powdery like drywall plaster.
It's even hard to wipe off your leg when it dries.
The roughness of the plywood might even help it stick.

Fingers crossed! Will be done an adhesion test this weekend so will report back

I'm going to message on a couple other posts as well but by chance does anyone know if home made clay interior house paint needs the sand added? I've seen a couple people say you don't have to use it for a smooth look finish but I've also seen some people say that it needs the sand to help prevent cracking etc.?

Again, I am an amateur,  but in your shoes I would simply try different mixtures in your tests