The silicate primer that evens absorbent mineral walls.

Substrate preparation — wall must be dry, clean, firm, and free from dust, grease, and loose material. Sweep, vacuum, and damp-wipe the surface. Cracks and large defects must be filled with mineral filler (LEINOS 684 interior smoothing filler) and allowed to dry per the filler’s TDS. Old loose paint or chalking dispersion coatings must be scrubbed back or stripped — 622 will bond to old strong-binding dispersion coatings, but not to flaking or powdering layers.

Stir thoroughly — stir the pail until any settled mineral solids are fully dispersed. Do not thin under normal conditions. On extremely absorbent substrates (very porous lime plaster, fresh clay rendering) the first pass may be thinned 5–10% with water for deeper penetration; subsequent passes go on at full strength. Apply at ambient and surface temperatures above 5 °C; protect from frost during application and the full drying window.

First coat — apply evenly with masonry brush, lambswool roller, or airless spray equipment. On heritage haveli walls and old lime plaster, brush is the canonical tool — it works the primer into the surface texture. On flat modern walls (gypsum board, smooth cement plaster), roller is fastest. For large commercial surfaces, airless spray covers ground quickly with even film build. Avoid puddles on lower-absorbency areas — surplus primer will not penetrate and leaves a sticky surface.

Wipe back any pooled primer — where the substrate has low absorbency (over-trowelled patches, smoothed corners, dense aerated-concrete blocks), the primer will pool on the surface rather than penetrate. After 15–20 minutes, brush or roll the pooled area back into the rest of the wall — distribute the surplus onto adjacent still-absorbent zones. No primer film must remain pooled on the surface after this step.

Touch dry 6–12 hours · recoatable 12 hours — touch dry after approximately 6–12 hours depending on temperature, humidity, ventilation, and substrate absorbency. Recoatable after approximately 12 hours. For most interior walls one coat is sufficient — the silicate has fused with the substrate and the surface reads uniformly absorbent. On highly variable substrates (heritage walls with multiple plaster patches, old painted walls with mixed history) a second thin coat after the first dries delivers the final uniform absorbency canvas.

Topcoat application — apply the chosen mineral topcoat per its own TDS once the primer is fully recoatable (12+ hours). Canonical topcoat partners: Lime Paint 665 (matt heritage lime finish), Natural Resin Emulsion Paint 660 (modern interior emulsion), Interior White Paint 650 (high-opacity matt emulsion). Each topcoat carries its own coat count and full-cure window — the primer is now a uniform, breathable, alkali-resistant substrate that lets the topcoat behave as intended.