ᐅ Primed Gypsum Plaster in New Construction — Silicification?

Hello everyone,

The handover of our house is coming up soon. We will be doing the painting and wallpapering ourselves and have already purchased the materials. Accordingly, I have been watching tutorials on how everything works. One question still hasn’t been answered for me, which concerns the pros and cons of gypsum plaster. We will be priming it with Brillux wall primer. And then? Can you basically apply anything you want after priming? I’m asking because of all these silicification processes. I know many people just paint directly with emulsion paint, but that’s generally not recommended. But what if you prime first?

I would appreciate your answers, thanks in advance.

We had a Q2 gypsum plaster finish. Of course, I applied filler and sanded it, then primed the surface and finally painted it twice with high-quality emulsion paint. No problems at all.

Silicification only works with mineral-based materials. Gypsum is not mineral-based. Almost all primers that contain any acrylic—most of them do—form a sort of skin. They would coat a particle that could theoretically silicify with, to put it simply, a very thin layer of plastic. This makes silicification impossible. So if gypsum is on the wall, it basically won’t silicify. However, you could still apply a mineral paint to the wall, but without the crystal-forming process of silicification.

Surprisingly, there are actually products on the market that contain both substances... and some people do buy them. I once knew a painter who, to enhance the mineral processes, added some binder to the material because he didn’t fully trust the silicification. Fortunately, his customer who caught him didn’t realize what he had done.

If a “normal” primer is applied, it will probably contain some acrylic. The binder in dispersion paint is also an acrylic in aqueous solution, used at a low concentration. Latex paint contains a bit more and is therefore washable. Pure acrylic binder in aqueous solution is still available but rarely used nowadays.

What is the intention of the question? To prevent the paint from coming off the wall?

...bingewatched... Yes, a nice little find 🙂... never heard of that before.

Best regards
Gabriele

Of course, gypsum is mineral-based. If you want to paint gypsum with a silicate paint, you need an additional pretreatment. Check the manufacturer's instructions for details. They offer products for this purpose. P.S. Most interior silicate paints are dispersion silicate paints.

@fach1werk: Your text is full of half-truths and prejudices. Yes, gypsum plaster is not ideal for silicate paint, but since most silicate paints, as already mentioned, contain a dispersion component, this can be managed. Due to the pH value, the paint still inhibits mold growth despite the organic component from the dispersion paint. Gypsum plaster alone does not develop mold, for example, because it is 100% mineral-based and 0% organic. There is nothing for mold to grow on. Gypsum plaster simply absorbs moisture, and if a dispersion paint is applied on top and dust (organic) accumulates, you then have a nutrient base.

I have earned my living for many years through mural painting, mostly using acrylics and occasionally mineral-based paints. My practical knowledge comes partly from seminars by Keim, but of course also from my own experience. Every time at the FAF, more materials appear that are supposedly all-in-one solutions, requiring no specific skills or knowledge, or that claim to replace multiple layers with a single application. This does not impress everyone equally.

When it comes to the chemistry, I am fully confident. You are probably an expert too, Michert. Thank you for your criticism. Please take a closer look. It’s worth it.

Best regards
Gabriele