What is Viscosity?

Viscosity is a term we often hear in the wood coating industry and it simply means how thick, or thin a wood coating is.

As you can imagine some liquids like honey are very thick and would take a long time to pass through a straw, while other liquids like water would pass through the same straw quickly. The thicker the liquid, the higher in viscosity we say that it is. So in that example, honey is a high-viscosity liquid and water is a low-viscosity liquid.

We discuss viscosity in wood coatings because thicker coatings are harder to spray through spray equipment and therefore often results in bubbles being trapped in the wood coating, or an orange peel-like texture which is caused because coatings don’t have enough time to flow and level. Thinner fluids, or those lower in viscosity, have their own potential problems such as running or sagging on verticle surfaces.

Each of our products works best at a specific viscosity, depending on the habits of the individual spray technician, their equipment, and the environmental factors of a specific workshop. Understanding what viscosity is, is the first step to understanding how to atomize wood coatings and get a perfect coating.

So we use the word viscosity to describe how thick, or thin, a wood coating is.

In this learning module, we will look at how to measure viscosity, what your viscosity should be for a wood coating, and how to change the viscosity of our products using additives.