How to Choose Liquid
Glass for Your Task

Liquid glass often evokes both hope and a bit of anxiety for those who work with it. It penetrates cracks, bonds materials, and protects against water and fire—but it can also ruin a batch of materials if chosen incorrectly.

In this article, we will break down the existing types, explain which parameters are vital, show you how to distinguish a suitable option from an unsuitable one, and share practical tips for achieving a stable result.

At STEKLOLUKS, we encounter these challenges daily while selecting silicate solutions for real-world production processes.

Liquid glass is an aqueous solution of alkali metal silicates. The primary carriers of the positive charge in the solution are sodium, potassium, or lithium ions. Many performance properties depend specifically on these ions.

In addition to the cation, the silicate module—the molar ratio of silica ($SiO_2$) to alkali metal oxide (M_2O)—is crucial. The module influences viscosity, adhesion, and the tendency to form a gel during neutralization.

When choosing, do not rely solely on price or the product name. While it is easy to check density or appearance, real performance depends on a specific set of parameters:

Sodium Silicate Solutions: The most common and cost-effective. They are widely used in construction, the manufacture of silicate paints, and various industrial processes.

Potassium Silicate Solutions: Usually more expensive, but they offer superior mechanical and thermal performance once hardened. They are chosen for coatings and products subjected to high temperatures.

Lithium Silicate Solutions: Used less frequently, typically for tasks with specialized requirements for thermal resistance or specific electrochemical properties.

The module is one of the main indicators.

• A low module (lots of alkali) gives a more fluid, reactive solution, but it is more aggressive to materials and resists moisture worse after hardening.
• A high module (lots of SiO_2) increases the water resistance and strength of the hardened layer, but such a solution is harder to apply and more expensive. The typical area of application dictates the required module.

Density helps to quickly evaluate concentration. The higher the solids content, the less water evaporation is needed for setting and the faster a film or gel is formed.

Viscosity is important during application: low-viscosity solutions penetrate pores and cracks more easily, while high-viscosity ones are more convenient for molding and sculpting. Manufacturers specify these parameters in product data sheets.

Oxide impurities—aluminum, calcium, iron, etc.—affect color, stability, and reactivity. For some tasks, the presence of small amounts of $Al_2O_3$ is acceptable; for others, the minimum possible content of foreign oxides is critically important.

If you plan to use the solution in electrochemically sensitive systems or in the production of refractories, request a certificate of analysis and an impurity specification.

Solutions have high alkalinity; this must be considered when choosing materials for tanks, pumps, and pipelines. pH also affects the interaction with acids and the curing methods.
If metallic additives are present in the formulation, be sure to confirm compatibility. Alkalis can corrode steel equipment during prolonged contact.

To avoid getting lost among names and brands, let's break down the applications into groups. This will help you understand which type makes sense to consider first.

For sealing, concrete impregnation, and the production of silicate binders, sodium solutions with a module of 2.0–3.2 are most commonly used. They interact well with cement and reduce water permeability.

For refractory mixes and heat-resistant coatings, higher-module and/or potassium compositions are chosen. They provide greater thermal resistance and are less prone to cracking when heated.

Potassium-based silicate paints form a thin, durable film and are often used for exterior facades and industrial coatings. Potassium enhances durability and resistance to weathering.

Sodium analogs are cheaper but require additional protection or specific surface preparation recommendations.

In foundry production, special formulas are used for cores and molds. Here, the curing speed and the ability to withstand high temperatures during pattern removal are critical.

For briquetting and granulation in metallurgy, formulations are chosen that provide strength and minimal ash content during firing.

In chemical and treatment processes, diluted solutions with controlled alkali content and no undesirable impurities are used. In household chemicals, complex mixtures with surfactant additives are often employed.

Important: For contact with drinking water, specialized formulations and strict certification are required.

To avoid getting lost among names and brands, let's break down the applications into groups. This will help you understand which type makes sense to consider first.

Below is a practical sequence of actions that saves time and minimizes the risk of error.

1. Determine the goal: waterproofing, binder, coating, impregnation, or technological additive.
2. Clarify the requirements for the final product: water resistance, thermal resistance, mechanical strength, acid resistance.
3. Check compatibility with other formulation components: cement, fillers, dyes, or organic additives.
4. Choose the approximate type by cation and module based on the task.
5. Request a quality data sheet and certificate from the supplier. Ask for a sample for technological testing.
6. Conduct technological trials under conditions as close to real ones as possible: application, curing, testing for strength and moisture permeability.
7. Evaluate long-term behavior: resistance to wet-dry cycles, thermal fluctuations, and aggressive environments.

In practice, three or four tests are sufficient to make a decision. The main thing is to reproduce real operating conditions. Typical trials include: adhesion test, water absorption test, compression or flexural strength test, and thermocyclic aging.

This is exactly how STEKLOLUKS verifies the suitability of a composition before launching it into industrial application.

If you want a quick result: take a standard sample of concrete or tile, apply the composition at the recommended dosage, let it dry, and check the bond during bending. This will provide a practical understanding of suitability.

To check the module and SiO_2 content on-site, acid precipitation is used: acid is added, and the amount of white silica precipitate is observed. This is a crude but functional method for primary assessment.

Alkaline solutions are demanding regarding storage conditions. Improper storage can change the composition and ruin the material even before application.

Store in a dry, cool room, avoiding direct sunlight. The optimal storage temperature is usually between 5–25 °C.

Choose corrosion-resistant containers: stainless steel or high-density polyethylene (HDPE). Steel equipment should not be used for long-term storage.

Work in gloves and safety goggles. Alkalis irritate the skin and eyes. In case of contact, rinse with plenty of water and seek medical assistance if necessary.

When working in enclosed spaces, organize supply ventilation — this will reduce the risk of respiratory tract irritation.

On the label, you will most often see density, solids content, and the silicate module. Sometimes a mass or molar module is indicated — pay attention to interpret the data correctly.

If the manufacturer provides only the mass module, remember that the molar ratio provides a more accurate representation of the molecular structure and reactivity of the solution.

A typical fragment: density 1.38 g/cm³, module $SiO_2/M_2O = 2.5$, solids content 35%, pH 11.5. This will give you an idea of the fluidity, corrosiveness, and tendency to form a gel.

If you see impurities in the oxides section — clarify the maximum allowable limit in your technological map. For some applications, even 0.2–0.5% $Fe_2O_3$ is critical.

Verify that the density and module match the data in the data sheet. Perform a simple test for gel formation by adding a small dose of acid — this will show the reaction rate.

If possible — send a sample to an independent laboratory for analysis of $SiO_2$ content and impurities. This is worth the expense, as it saves dozens of times over in mass application.

One simple working recipe: diluted sodium liquid glass with a module of 2.5, an addition of 1–2% plasticizer, and a hardening accelerator in the form of an acid solution in an aqueous dispersing agent, introduced locally.

Such a mixture penetrates the crack and creates a hydrophobic gel. Important: select the accelerator dosage experimentally to avoid premature thickening in the mixture.

We recommend asking these questions before purchasing silicate solutions—this is how a correct technical assignment is formed. Below is a brief set of questions that significantly reduces the risk of error during selection.

1. What is the purpose of application and what are the requirements for the final product?
2. What silicate module is suitable for this task?
3. What are the permissible oxide impurities, and is certification required for contact with drinking water or food?
4. Is it possible to conduct technological trials with samples before purchase?
5. Is the supplier ready to provide a quality data sheet and assistance in selecting the formulation?

If the answers to these questions are clear, you are already significantly closer to the right choice. Small investments in testing pay off by avoiding the need to re-lay or rework finished products.
Liquid glass is an ambiguous material: the right choice brings a stable result, while the wrong one can be costly. Approach the selection systematically, rely on specific parameters, run trials, and do not skimp on quality control. Then the material will truly start working for you.
If you need to select liquid glass for a specific task or technology, STEKLOLUKS specialists will help determine the optimal parameters and offer a solution tailored to your operating conditions.