Please note: It is important that all Wet Film Thickness readings are taken immediately or shortly after the gun has passed over the spot to be measured. This is especially important when using quick curing coatings.
Follow these very simple steps:
Select scale range
Place gauge on wet film at 90 degree angle
Press into film
Withdraw and note deepest tooth having paint on it and next higher tooth that is not coated
The wet film thickness lies between these two readings
Clean gauge in any suitable solvent immediately after use.
The diagram above indicates that the tooth marked 3 mils is covered with the wet paint and the tooth marked 4 mils is not covered. This indicates that the true wet film thickness of the material is between 3 and 4 mils thick.
Also note that the gauge should not be dragged through the coating - this will cause a high reading. When being used on a pipeline or similar curved surface, the gauge must be placed along the longitudinal axis.
For Clear Coatings
To see clear liquids on the teeth, sprinkle them with talcum powder and blow off. Talc will stick to the wet teeth.
Dry Film to Wet Film Thickness Ratio
The generally accepted ratio of dry film to wet film thickness of most coatings is: