Physical properties of sodium silicate-based substances make them very attractive for commercial/industrial use. Liquids and solids based on sodium silicate and produced by PQ Corporation have a density from 1.6g/cubic cm. to about 1.4 g/cubic cm.
A very big difference between acrylic and oil paint is the drying time. Acrylics dry in a matter of minutes to hours and oils dry in a matter of hours to weeks! This is a huge factor when choosing whether or not to choose oils versus acrylics.
It is a known fact that using acrylic on top of oil paint is a bad practice. Conservators warn against this practice as the oil paint underneath continues to dry. This drying causes a shrinking of the painting surface underneath the acrylic which dries much faster.