This Wet Film Thickness Gauge is an important tool to measure the depth of paint and coatings applied to substrates to ensure the correct thicknesses are applied.
When applying paint or coatings to substrates, this tool should be embeded in the paint to measure the depth of the coating. This is extremely important when applying intumescent paint coatings as their performance is dependant upon the correct thickness of paint being applied to the steelwork. This wet film thickness is calculated by the intumescent specialist at Promain. Some products will have predetermined WFT's that are published on the manufacturers product data sheet.
What Is Film Thickness?
Film thickness refers to the thickness of an individual wet or dry film. Film thickness can also refer to the thickness of a paint system. Film thickness is presented as micrometres (μm) or millimetres (mm).
The corrosivity category, the paint type, and the desired durability time specify the film thickness of a paint system. In painting standards, paint system specifications and technical data sheets, the film thickness is indicated as the DFT - Dry Film Thickness. EN ISO 12944-5 (section 5.4) specifies the nominal dry film thickness. Wet Film Thickness is determined using a wet film thickness gauge. The thickness of dry film can be measured applying either a destructive or non-destructive method.
As the standards specify the inclusion of the surface profile in the dry film measurement in different ways, it is important to agree upon the applicable standard and specification. The film measurement methods are described in ISO 2808.
Film thickness can be monitored during application using a wet film measurement gauge. Wet film measurement is carried out using a wet film comb immediately after application or before solvent evaporation of a coating. The measurement method is described in ISO 2808. The wet film thickness value (Km) can be read directly from the comb.
Press gauge into the wet coating. Withdraw the tool vertically and note the deepest tooth with paint on it and the next highest tooth that is not coated with paint. The true wet film thickness lies between these two readings. Clean gauge with a suitable solvent after each use to ensure correct readings.
For WFT requirements, please refer to the individual paints and coatings data sheet prior to use.
How To Calculate Dry Film Thickness
Dry film thickness (Kk) can be calculated using the formula:
(1) Kk = Km V/100 (μm)
V is the percentage of solids by volume. The percentage of solids content in the paint (V) is given in the technical data sheet, and the wet film thickness Km is provided by the measurement.
Allows for measurements of:
- 50 - 800 microns
- 2 - 32 thousands of a millimetre
- Each comb has 16 measurement steps
- Material: ABS Plastic
- Tool Size: 40 x 40mm
- Available as an individual tool
The manufacturers data sheets are available for download from this website. It is your responsibility to read and understand all aspects of the data sheets before you place an order and prior to application. Please pay special attention to the preparation, mixing and application temperatures of the product, cleaning of substrate and environmental factors such as temperature, rain etc. Quoted coverage rates are based on the manufacturers theoretical rates and may vary depending upon substrates absorption, texture and application. We always recommend a test is carried out to ensure suitability.
Customer further agrees that Promain have no liability for any errors or omissions contained within the Product Data Sheets and are not liable for failure due to misapplication or inadequate substrate cleaning and preparation. For more information please refer to our Terms & Conditions.