Water glass | Glass varnish | Kiesol | Sodium metasilicate (5.0 L)

Buy Water Glass / Glass Varnish / Sodium Metasilicate (Kiesol, Sodium Water Glass)

Looking to buy water glass for professional use? This is a versatile alkaline silicate solution, also known as sodium metasilicate or kieselguhr. It’s supplied as a concentrated liquid and reacts directly with free calcium in cementitious materials. The substance forms a very dense CSH network in concrete and mortar, drastically reducing moisture absorption. Perfect for waterproofing, surface impregnation, injections to combat rising damp, and as an additive in mortar and concrete formulations.

Product specifications

• Product Name: Water Glass / Glass Varnish / Sodium Metasilicate
• Also known as: Kiesol, Sodium water glass, Sodium silicate, Liquid glass, Sodium silicate
• CAS number: 1344-09-8 (technical) / 6834-92-0 (pure anhydrate)
• EC number: 215-687-4
• Purity / Quality: Technical, ≥99%
• Form: Concentrated transparent to slightly opalescent alkaline liquid
• Delivery: Concentrated solution
• Application: For mortar and concrete reinforcement, injections against moisture absorption, surface impregnation
• Yield: Depending on the application, 1 litre covers an average of 5-10 m² when impregnating.

What is Water Glass / Sodium Metasilicate used for?

Water glass is used as an additive in mortar and concrete in professional construction and renovation projects. Addition to the mixing water in diluted form (typically 2–5% of cement weight) influences the microstructure of the cement paste and contributes to a denser matrix. This is relevant in prefab applications, repair work and special applications cement formulations.

For existing mineral structures, it is used as an injection fluid for moisture control. In a diluted form, the solution can penetrate the material and react with existing calcium compounds. It is also used in the surface impregnation of concrete and stone substrates to influence pore structure and water absorption.

In addition, water glass is used in an industrial context as an alkaline additive in cleaning agents, detergents and technical formulations where silicate structures are functional.

Chemical properties

• Chemical formula: Na₂SiO₃ or Na₂O·SiO₂ (anhydrate) / Na₂SiO₃·nH₂O (hydrated)
• Density: approx. 1.38-1.42 g/cm³ (40% solution at 20 °C)
• Melting point: approx. 1,088 °C (anhydrate)
• Boiling point: Not applicable; water evaporates, silicate decomposes at high temperature
• Flash point: Not applicable (non-flammable)
• Solubility: Completely miscible with water; forms a strongly alkaline solution (pH approx. 11-12.7 depending on concentration)

Storage and use

Store in the original, tightly closed jerrycan, protected from atmospheric carbon dioxide to reduce carbonation and thickening. Store in a cool, dry place, preferably below 25°C. Keep away from acids and reactive metals such as zinc and tin.

Use only in professional environments with appropriate dosing and safety equipment. Dilute the product according to the application and use within the specified processing times. Ensure adequate ventilation due to its highly alkaline nature.

Instructions for use

• Mortar/concrete: 2-5% (diluted) based on cement weight, add to mixing water
• Injection Application: 1:1 dilution with demineralized water, processing via boreholes
• Surface impregnation: 1:1 to 1:2 dilution with water, apply with a roller or spray, allow to dry for at least 8 hours

Health and Safety

Danger

Hazard statements (H-statements)

• H318: Causes serious eye damage.
• H315: Causes skin irritation.

Precautionary statements (P-statements)

• P264: Wash thoroughly after handling this product.
• P280: Wear protective gloves/protective clothing/eye protection/protective footwear.
• P302+P352: IF ON SKIN: Wash with plenty of water.
• P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
• P310: Immediately call a POISON CENTRE/doctor.
• P321: Specific treatment (consult a physician with the Safety Data Sheet of this product).
• P332+P313: If skin irritation occurs: Get medical advice/attention.
• P362+P364: Remove contaminated clothing and wash before reuse.

Frequently Asked Questions (FAQ)

How do I dilute water glass for different applications?
The dilution depends on the application: 2–5% for mortar, 1:1 for injection and 1:1 to 1:2 for surface treatment.

Is water glass flammable?
No, it is a water-based inorganic silicate solution that is not flammable.

Can water glass be applied to metals?
Steel and stainless steel are usually suitable; avoid contact with zinc and tin because of possible reactions.

How long does an opened jerry can last?
When stored tightly closed under suitable conditions, the product can remain usable for a longer period of time; visually check for thickening.

More Information

For additional information about the chemical properties and applications of Water Glass / Sodium Metasilicate, please contact: PubChem – Sodium Silicate.