It is easy to predict the thickness of the paint once it dries. All that is required is that you know the "Volume-Solids Percentage" of the paint, and that you have a "Wet Film Thickness Gauge". The volume-solids of a paint (not to be confused with "weight-solids") is listed on the product data sheet, which can be found on the paint manufacturer's website. "Wet Film Thickness" (WFT)
WFT Specifications In a previous post I discussed "paint volume solids", which I described as "the substance that remains after the paint dries". In that article, I explained that when paint dries it shrinks in proportion to its volumetric solids. For example, a paint with 50% solids will lose half of its volume as it dries. If it is 4 mils wet, it will be 2 mils thick (4 x 50%) when dry. Paint Roll Solids Wet Film Thickness Fortunately, the wet film thickness (WFT) of a coating can be easily measured using a wet Film Thickness Gauge.
To use a WFT comb gauge, you press the graduated edge of the gauge into the wet coat immediately after application. Take it out vertically and notice that the deepest teeth are painted, the next taller serrations are not. The true wet film thickness is somewhere between these two readings.
In the United States, the thickness of paint is expressed in mils (1 mil equals 1/1000th of an inch). The rest of the world expresses coating thickness in microns (1 micron = 1 millionth of a meter and 25.4 microns = .001 inches or 1 mil). The table below compares the thickness of common materials in mils and microns.
Being able to predict the thickness of paint has many practical benefits:
It ensures that you use the correct amount of paint to achieve the performance of your paint.
Coating thickness is related to drying time, recoating time and appearance.
And, the ability to predict paint thickness can help you control costs.
