Project notes
Understand this estimate
The brush-on estimate treats the mold skin as a uniform thin shell: measured three-dimensional surface area multiplied by a specified shell thickness.
How to use the calculator
Measure the full contoured surface
Measure the surface that will receive rubber, including contours; a front-view silhouette is not the same as surface area.
Inputs Contoured surface area
Enter the specified shell thickness
Use a procedure or product instruction for this project. The input is not a universal recommendation.
Inputs Specified shell thickness
Enter the product density and allowance
Use density from the selected mixed material data. Add an explicit project allowance only if needed.
Inputs Mixed material density · Extra allowance
Formula and variables
Thin-shell volume ≈ measured surface area × specified shell thickness. Convert square feet to square inches, then convert in³ to mL (×16.387064) and multiply by the entered mixed density.
- AContoured area
- Full surface area to be covered.ft²
- tShell thickness
- Entered uniform thickness.in
- ρMixed density
- Product-specific material density.g/mL
What the result means
Result interpretation
The geometric volume and mass are thin-shell estimates. The model does not include keys, support shells, pooling or variation in thickness.
Limits and assumptions
This thin-shell estimate does not model varying thickness, keys, registration features, support shells or local material pooling. The thickness input is not a universal recommendation.
Worked example
A 2 ft² shell at 0.375 inch
Assumptions
- Surface area is 2 ft² and thickness is uniform at 0.375 in.
- Mixed density is 1.1 g/mL; the entered allowance is 10%.
Calculation
- 2 × 144 × 0.375 = 108 in³.
- 108 × 1.10 = 118.8 in³.
- 118.8 × 16.387064 × 1.1 = 2,141.5 g = 75.54 oz.
| Geometric shell volume | 108 in³ |
|---|---|
| Volume with allowance | 118.8 in³ |
| Estimated mixed material | 75.54 US oz |
| Estimated mixed material metric equivalent | 2,141 g |
Common questions
- Can I measure only the front outline?
- No. Use the complete contoured surface area that receives material.
- Does the estimate include a support shell or registration keys?
- No. Only the entered skin thickness is modeled.