Preparing a cheap fireproof mortar for laying a stove or fireplace

The use of refractory brick does not guarantee that a stove or fireplace made from it will last for a long time without cracks. The mortar used for laying is no less important. Ready-made heat-resistant mixtures in bags are quite expensive, but in terms of performance they are no better than a simpler, cheaper solution that you can make yourself. If you want to save money without losing quality, you can make a heat-resistant masonry mixture yourself based on the inexpensive MSh-28 mortar and sodium liquid glass.

Materials:

water;
sodium liquid glass;
mortar MSh-28.

The process of preparing a heat-resistant solution

Liquid glass must be mixed with water in a 1:1 ratio. The components mix well when shaken in the bottle. The required amount of diluted liquid glass can be prepared at a time, and it can be added to the solution as needed, since it does not lose its quality.

Next you need to close the MSh-28. You need to use yellow mortar, not gray. The latter requires different proportions. 6.5 liters of water are poured into 25 kg of MSh-28.Water is poured from above and a short pause is made so that it saturates the mortar. This will prevent the formation of lumps, which would otherwise take a long time to break up. Next, the mixture is mixed with a mixer until smooth and left for at least 3 hours for the clay to swell. You can safely leave it overnight; it won’t set, but on the contrary, it will only get better.

After swelling, the mortar is mixed again. Then 250 mm of liquid glass solution with water is poured in. After this, the mixture is mixed with a mixer for at least 3 minutes. It is not worth pouring 125 ml of liquid glass at once, since stirring it in a thick mass until it has a homogeneous consistency will take a lot of time and effort.

After waiting 20 minutes, you need to mix the solution again and it is ready for use. With this proportion it obtains a consistency very convenient for masonry. The solution does not float, nor is it overly thick. It's a pleasure to put on it. Although the solution takes a long time to prepare, if the work is planned correctly, it will not create inconvenience. You can mix 25 kg of MSh-28 in a bag of water in the evening, and then in the morning, as needed, add liquid glass to it and produce it. This solution is guaranteed to be heat-resistant and easy to work with; moreover, it is not expensive, which cannot be said about ready-made store-bought mixtures.