Fondosilk is a formulated modified stabilizing fluosilicate, conform to the din 18363. 

This binder can regulate the absorption, it profoundly stabilizes the background, guarantees the ideal bond of the final coat, and does not reduce the vapour permeability. 

Thanks to its mineral properties, it allows the silicate paint to bond deeply with its substrate.

Fondosilk penetrates deep into the background and crystallizes firmly with it.

Fondosilk is a natural inorganic liquid product. 

Application area

Fondosilk is mainly used as a stabilizer and preparation coat for all kinds of mineral substrates 

Such as lime mortars, cementitious and bastard mortars, brickwork and most natural stonework.

It can also be used as dilution for the corisilk.

Apply fondosilk in one or two coats, diluted with max. 50 % of clean water for dense substrates with low porosity and bad absorption. You can apply fondosilk by means of a brush or paint-spraying (airless) equipment. Do not apply fondosilk to surfaces exposed to strong winds or direct sunlight, nor in case of heavy fog or temperatures under +5°c or over +35°c, nor on frozen and humid backgrounds. Avoid applying this product in rainy conditions. 

Preparation of the substrate and Application

Stable, clean surfaces – such as lime renders and plasters, lime washes as well as traditional masonry in brick or natural stone built with lime mortar – do not require any prior treatment.  Powdery layers must be removed until a sound substrate is reached.  Stone repairs, repointing and repairs to damaged brickwork and/or loose renders are preferably done by means of natural hydraulic lime mortars first.  

In order to prepare an unstable substrate, a layer of Fondosilk is applied.  In case of a porous and absorbent surface, a layer of Fondosilk is applied, diluted with maximum 50% of water.  Fondosilk is also applied as a base coat on unequally absorbing surfaces.

When surfaces are very dry and climatic temperatures very high, we recommend that the surfaces are dampened down prior to the application of Fondosilk silicate binder.

Do not apply Fondosilk silicate binder to surfaces exposed to strong winds or direct sunlight, nor in case of heavy fog or temperatures under +5°C or over +35°C.  Immediately clean tools in water and soap.


Indicative consumption: 0,100 to 0,200 l/m².

The average coverage per litre of silicate paint amounts 6 to 8 m².

Packing and storage

Plastic jerry cans of 1 litre, 5 litres and 25 litres.

The stability of the silicate binder is at least 6 months provided that it is stored in airtight closed containers and suitable environmental conditions.  Store in a cool and dry environment, well protected from frost and direct sunlight.  Protect from heat sources.

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