Is the absorbency uneven, causing blotchy paint? The mixed substrate absorbs the color differently in places. This fine silicate primer evens out the absorbency. It does not compromise the surface strength. This is the fine leveling primer of the Biocalce silicate system.
-
Patchy absorbent, mixed substrate: finely levels it — the silicate paint color will be even, no blotches show through
-
Part of the system: the fine leveling primer of the Biocalce silicate system — applied over Biocalce Silicato Consolidante, under the silicate paint
-
Smooth, sound surface: does not compromise it — does not change the appearance or strength of the surface, thin, fine layer
-
Old, new, and repaired patches on one wall: uniform absorbency everywhere — partially renovated surfaces also paint uniformly
-
Naturally breathable — the wall breathes freely even under the paint
-
Easily adjustable: can be diluted with water up to 25%, or with Biocalce Silicato Consolidante 10–15% according to substrate porosity
-
Primer, not finishing: the color and decorative surface are provided by the Biocalce Silicato Puro Pittura silicate paint
| Type |
Fine silicate leveling primer (for exterior and interior) |
| Binder |
Pure potassium silicate (DIN 18363) |
| Performance |
Even absorbency
Naturally breathable |
| Material requirement |
≈ 0.1–0.2 l/m² per coat
4 l ≈ 20–40 m², 14 l ≈ 70–140 m² |
| Packaging |
Bucket 4 l and 14 l |
| Storage |
≈ 6 months |
What is it suitable for?
Substrates: Sound, solid mineral surfaces — new, cured, healthy plasters, spot or partially renovated surfaces, porous materials with varying absorbency, historic plasters. Where the surface is already smooth and solid, only absorbency needs to be unified.
Spaces: Exterior and interior — facades and interior walls, restoration, renovation where fine, appearance-neutral leveling is needed before silicate painting.
Function in the system: The fine leveling primer of the Biocalce silicate system. It is applied over the consolidating primer and under the silicate surface, without compromising the surface strength.
Not suitable for:
- As a standalone finished surface (without silicate paint) — this is a primer, not a decorative layer
- On damp, unseasoned substrate
- On contaminated, loose, dusty surface
- On old paint or decorative whitewash
- On gypsum-based substrate
- For walls exposed to capillary moisture — first a moisture-proof plaster (Biocalce Zoccolatura / Benesserebio) is needed
The Biocalce silicate system
Biocalce Silicato Fondo Fino is the fine leveling primer of the silicate system. The possible breathable build-up:
Not every primer is always necessary — the condition of the substrate decides. Silicato Fondo Fino gently evens out moisture absorption on smooth, intact surfaces without compromising strength. On dusty, weak substrates, first consolidate with Biocalce Silicato Consolidante; on uneven, cracked surfaces, use the filler Biocalce Silicato Fondo instead. The exact layering is specified by the substrate and the Kerakoll system description.
Which silicate primer is needed?
-
Consolidation of dusty, weak, crumbling substrate: Biocalce Silicato Consolidante — deeply consolidates
-
Uneven substrate + crack bridging: Biocalce Silicato Fondo — filler, W3 rain-resistant
-
Fine, even moisture absorption without damaging the surface: Biocalce Silicato Fondo Fino — this product is a thin, leveling
Frequently Asked Questions (FAQ)
Why does silicate paint become blotchy on plaster?
Because the substrate absorbs moisture unevenly. The mixed surface absorbs the paint differently in places, causing the color to be blotchy. A fine leveling primer evens out moisture absorption.
Which silicate primer is needed for smooth, sound substrates?
The fine Silicato Fondo Fino unifies absorption but does not change the appearance or strength of the surface. A different primer is needed for dusty or cracked substrates.
What is the difference between Silicato Fondo and Fondo Fino?
Biocalce Silicato Fondo fills and bridges cracks on uneven surfaces. Fondo Fino is fine and thin — it only evens out absorption and does not alter the smooth surface. Use Fino on sound substrates, Fondo on uneven ones.
Is a consolidating primer needed under Fondo Fino?
On absorbent or weaker mineral substrates, yes: first Biocalce Silicato Consolidante consolidates the surface. On sound, solid substrates, Fondo Fino can be applied directly.
Is a topcoat needed over the leveling primer?
Yes. Fondo Fino is a primer, not a finished surface. The Biocalce Silicato Puro Pittura silicate paint goes on top.
How much primer is needed, how many m² does it cover?
Per coat ≈ 0.1–0.2 l/m². The 4-liter covers ≈ 20–40 m², the 14-liter ≈ 70–140 m². The exact amount depends on the substrate.
Is lime or silicate primer needed?
The decorative surface decides. For silicate painting (Biocalce Silicato Puro Pittura), a silicate primer is needed — this product belongs to that system. For lime painting or lime noble plaster (Biocalce Tinteggio, Biocalce Marmorino), a lime primer is required: Biocalce Fondo or Biocalce Fondo Universale.
When should I not use it?
Do not apply on wet, dusty, or contaminated substrates, gypsum, or old paint. Also not on walls with rising moisture — those require a moisture-proof plaster first.
Can it be purchased separately?
Yes. You can also purchase it if you already have the other system products, if you are preparing an existing surface, or if you have a small leftover from a project.
Can I apply it myself?
Yes — with a brush or wool roller, in one or two coats. Exterior work requires scaffolding and practice. We also carry out the complete silicate system.
