sodium silicate

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sodium silicate, sodium metasilicate, water glass, liquid glass, Na2SiO35H2O, or, more correctly, Na2SiO2(OH)2·4H2O


glossary

OPC
Ordinary Portland cement

concentrations of sodium silicate to water for various applications

Na2SiO3

sodium silicate pentahydrate, Na2SiO3·5H2O, is the common commercial variant most often seen. Note that the dried prills without packing are nearly the same density as water, so it's a good rough approximation to measure by volume.

chemical gardens
3:2 (by weight sodium silicate:water)
refractory cement
1:1 by weight
casting
1:1 by weight
cement floor sealer
1:4 by weight


dissolving sodium silicate in water

Dry sodium silicate does not readily dissolve in water. Heating the water will allow the sodium silicate to dissolve much more quickly.

Note that I read that at a certain temperature the sodium silicate may become reactive and convert to some other chemical. I'm not sure what this means. I may have misread the source, which I have lost. I need to research this more.

refractory cement

Potassium silicate and Calcium silicate may also be used instead of sodium silicate. A higher silicate:alkali ratio gives faster setting time, while lower ratios give greater strength in the finished product.

An aqueous solution of sodium silicate and vermiculite or perlite can be combined to form a cement or casting material that will withstand the temperatures of a kiln. The sodium silicate forms a fireproof cement; however, it needs a curing or setting agent to harden the sodium silicate.

Gas
Carbon dioxide
Liquid
Glycerol Diacetate plus either Glycerol Triacetate or Ethylene Glycol Diacetate
Solids
Calcium silicates (Portland cement), Calcium Sulphate (gypsum), Silicides such as Ferrosilicon or Calcium Silicide, Silicofluorides or fluorosilicates, heavy metal salts such as carbonates or phosphates, other sources of multivalent metal cations such as Ca+2, Mg+2, Zn+2, Cu+2, Fe+3.

Note that ordinary portland cement provides Calcium ions which will almost instantly set Sodium Silicate. Adding a small amount of cement or plaster to an aggregate mix of Sodium Silicate and vermiculite will cause the mixture to set in just a few minutes.

Sources

Common TSP substitute is often Sodium Metasilicate. This is available in any hardware store.