Project notes
Understand this estimate
Wet-film thickness estimates the liquid layer needed to reach a dry-film target after the coating loses its nonvolatile liquid. Volume solids and any label-defined reducer affect the relationship.
How to use the calculator
Enter the target dry-film thickness
Use the project specification or current product instructions.
Inputs Target dry film thickness
Enter product volume solids
Use the current technical data sheet value, expressed as a percentage.
Inputs Volume solids
Include reducer only on the stated basis
Enter reducer as a percentage of base coating volume only when the instructions define it that way.
Inputs Reducer added
Formula and variables
WFT = target DFT × (1 + reducer percentage ÷ 100) ÷ (volume solids ÷ 100).
- DFTTarget dry-film thickness
- One mil is 0.001 inch.mil
- VSVolume solids
- Nonvolatile volume fraction from the product data.%
- rReducer added
- Optional label-defined reducer amount.% of base
What the result means
Result interpretation
Required wet-film thickness is a theoretical conversion. The page does not choose a target film build or account for transfer loss, substrate profile or application technique.
Limits and assumptions
This is a theoretical film conversion based on volume solids. It does not determine a suitable film build, account for transfer loss or replace the product data sheet and wet-film gauge.
Worked examples
Four-mil dry target at 60% solids
Assumptions
- Volume solids are 60%.
- No reducer is added.
Calculation
- 4 ÷ 0.60 = 6.6667 mil wet film.
| Required wet film thickness | 6.667 mil |
|---|---|
| Target dry film thickness | 4 mil |
| Volume solids after reducer | 60 % |
Same target with 10% reducer by base volume
Assumptions
- The product allows the entered 10% reducer basis.
- Target dry film remains 4 mil.
Calculation
- 4 × 1.10 ÷ 0.60 = 7.333 mil wet film.
- 60 ÷ 1.10 = 54.545% effective solids after reducer.
| Required wet film thickness | 7.333 mil |
|---|---|
| Target dry film thickness | 4 mil |
| Volume solids after reducer | 54.55 % |
Common questions
- Is a higher wet-film target always better?
- No. Use a specified product target and thickness range; this calculator does not determine suitability.
- Does the result account for spray transfer efficiency?
- No. It is a theoretical film conversion, not a wet-film gauge reading. Check applied WFT with an appropriate gauge and compare it with the exact coating instructions.
- How are dry-film and wet-film thickness related without reducer?
- The theoretical relationship is DFT = WFT × volume-solids fraction. The calculator rearranges it to solve for WFT; it does not verify the film actually applied.