Histolith Fluat

Liquid fluosilicate concentrate for render/plaster pre-treatment.
LV Texte

Field of Application

Acid fluate (fluosilicate/fluorosilicate), suitable for removing sintered layers/skin on new renders/plasters before applying silicate paints and also applicable for the neutralisation of render/plaster surfaces. Furthermore useable for cleaning existing mineral renders/plasters and coats of mineral paint.

Material Properties

Histolith® Fluat reacts with lime and cement based renders/plasters. In the process all acid ingredients will be neutralised. The washing water is acid-free, when the product is applied in a proper way.

Material Base / Vehicle

Aqueous solution of acid fluosilicates (fluorosilicate solution).

Packaging/Package Size

10 litres


Keep in a cool, but frost-free place.
The product must be stored in acid-resistant cans/containers. Do not use other receptacles. 


Approx. 1.2 g/cm³

Suitability according to Technical Information No. 606 Definition of Application Areas

Interior 1Interior 2Interior 3Exterior 1Exterior 2
(–) inapplicable / (○) of limited suitability / (+) suitable

Suitable Substrates

The substrate must be absorbent, solid/stable, dry, clean, and free from all substances that may prevent good adhesion. In Germany: Follow VOB, part C, DIN 18 363, section 3.

Substrate Preparation

New Renders/Plasters in Mortar Groups/Classes PI (Lime Plasters),
PII (Lime-Cement Mortars) and PIII (Cement Mortars):
New renders/plasters must be left untreated for a sufficiently long holding time, minimum 4 weeks for mortar group PI and minimum 2 weeks for mortar groups PII and PIII. Then remove sintered layers/skin with Histolith® Fluat.

Untreated Existing Renders/Plasters in Mortar Groups/Classes PI, PII, PIII
and Coats of Mineral Paint:
Sintered layers/skin and soiling/impurity has to be removed with Histolith® Fluat before applying subsequent coats.

Method of Application

Dilute Histolith® Fluat with 3 to 5 parts of tap (potable) water and apply by paint brush from bottom to top. Maximum allowable reaction time: 5 - 10 minutes, drying should be avoided.

Allow to react, then rinse liberally with clean water.
In individual cases the procedure must be repeated to remove all residues of sintered skin or impurity. Catch all washing water in suitable collection containers and dispose of in accordance with current local waste regulations.


Approx. 30 - 50 ml/m2 according to substrate requirements.

Application Conditions

Lower Temperature Limit for Application:
+8 °C for product, substrate and ambient air.

Drying/Drying Time

Allow to dry thoroughly for minimum 12 hours. Apply subsequent coats only when the substrate is fully dry.

Tool Cleaning

Clean tools/equipment immediately after use with water.


Do not use on (sun) heated surfaces.

Protective Measures:
The areas adjoining the surface to be treated/painted should be carefully masked, in particular glass, ceramics, enamel/varnish coatings, clinkers, natural stone, metals and wood.

Special Risks (Hazard Note) / Safety Advice (Status as at Date of Publication)

For professional use only.
Danger. Contains hexafluorosilicic acid. Causes severe skin burns and eye damage. Do not breathe vapours/spray. Do not get in eyes, on skin, or on clothing. Avoid release to the environment. Use personal protective equipment as required. IF ON SKIN: Wash with plenty of soap and water. Store in a well-ventilated place. Keep container tightly closed.


Materials and all related packaging must be disposed of in a safe way in accordance with the full requirements of the local authorities. Particular attention should be made to removing wastage from site in compliance with standard construction site procedures.
In Germany: Only completely empty cans/containers should be handed in for recycling. Do not dispose via domestic waste.
Do not empty into drains.
European Waste Code (EWC) 060106 (waste of inorganic chemical processes; waste of production, preparation and application of acids; other acids).

Further Details

See Material Safety Data Sheet (MSDS).

Technical Assistance

As it is impossible to list herein the wide variety of substrates and their specific problems, please request our technical assistance in case of queries. We will describe appropriate working methods, if a substrate not specified above is to be coated.

Customer Service Centre

Tel.: (+49) 0 61 54 / 71 17 10
Fax: (+49) 0 61 54 / 71 17 11

International Distribution: Please see

Technical information

Material safety data sheet