The approximate coverage area depends on how much material is contained in a unit (A+B by weight) and what the material yields on a cubic inches per lb. (or cubic meters per kilogram) basis. Since each brushable mold rubber has a different yield, coverage rates will vary.
The following offers flat-area coverage rates for some of Smooth-On's brushable mold making rubbers. The below values assume a final rubber thickness of 3/8" (1 cm) – 4 layers of rubber applied as directed.
Rubber Product Coverage
- Mold Max® STROKE - 1 Gallon Kit (11 lbs. / 4.99 kgs.): 4.8 ft² / 0.45 m²
- Mold Max® STROKE - 5 Gallon Kit (55 lbs. / 24.95 kgs.): 24 ft² / 2.23 m²
- Rebound™ 25 - 1 Gallon Kit (18 lbs. / 8.16 kgs.): 7.8 ft² / 0.72 m²
- Rebound™ 25 - 5 Gallon Kit (90 lbs. / 40.82 kgs.): 39.2 ft² / 3.64 m²
- Rebound™ 40 - 1 Gallon Kit (18 lbs. / 8.16 kgs.): 7.8 ft² / 0.72 m²
- Rebound™ 40 - 5 Gallon Kit (90 lbs. / 40.82 kgs.): 39.2 ft² / 3.64 m²
- Brush-On® 35 - 1 Gallon Kit (13.4 lbs. / 6.08 kgs.): 5.3 ft² / 0.49 m²
- Brush-On® 35 - 5 Gallon Kit (75 lbs. / 34.02 kgs.): 29.9 ft² / 2.78 m²
- Brush-On® 40 - 1 Gallon Kit (18 lbs. / 8.16 kgs.): 7.9 ft² / 0.73 m²
- Brush-On® 40 - 5 Gallon Kit (90 lbs. / 40.82 kgs.): 39.5 ft² / 3.67 m²
- Brush-On® 50 - 1 Gallon Kit (18 lbs. / 8.16 kgs.): 7.9 ft² / 0.73 m²
- Brush-On® 50 - 5 Gallon Kit (90 lbs. / 40.82 kgs.): 39.5 ft² / 3.67 m²
- Brush-On® 60 - 1 Gallon Kit (18 lbs. / 8.16 kgs.): 7.8 ft² / 0.72 m²
- Brush-On® 60 - 5 Gallon Kit (90 lbs. / 40.82 kgs.): 39.2 ft² / 3.64 m²
Doing the Math
Below are some examples for how these coverage rates can be calculated by hand. The first step is to calculate the total cubic inch yield of a kit (Net Weight times Specific Volume). Then, divide out the mold thickness (3/8"). Lastly, convert square inches to square feet.
How many square feet will one 5-gallon unit (90 lbs.) of Rebound® 25 or 40 brush-on silicone rubber cover at 3/8" thickness?
- 90 lbs. x 23.5 cubic inches per pound = 2,115 in³
- 2,115 in³ ÷ 0.375 in. (3/8") = 5,640 in²
- 5,640 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 39.2 ft²
39.2 square feet is the coverage of a 5-gallon unit of Rebound® 25 or 40 applied 3/8" thick.
One-gallon Unit (18 lbs.) Coverage
- 18 lbs. x 23.5 cubic inches per pound = 423 in³
- 423 in³ ÷ 0.375 in. (3/8") = 1,128 in²
- 1,128 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 7.8 ft²
7.8 square feet is the coverage of a gallon unit of Rebound® 25 applied 3/8" thick.
How many square feet will one 5-gallon unit (75 lbs.) of Brush-On® 35 urethane rubber cover at 3/8" thickness?
- 75 lbs. x 21.5 cubic inches per pound = 1,612.5 in³
- 1,612.5 in³ ÷ 0.375 in. (3/8") = 4,300 in²
- 4,300 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 29.9 ft²
29.9 square feet is the coverage of a 5-gallon unit of Brush-On® 35 applied 3/8" thick.
One-gallon Unit (13.4 lbs.) Coverage
- 13.4 lbs. x 21.5 cubic inches per pound = 288.1 in³
- 288.1 in³ ÷ 0.375 in. (3/8") = 768.27 in²
- 768.27 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 5.3 square feet
5.3 square feet is the coverage of a gallon unit of Brush-On® 35 applied 3/8" thick.
How many square feet will one 5-gallon unit (90 lbs.) of Brush-On® 40 or 50 urethane rubber cover at 3/8" thickness?
- 90 lbs. x 23.7 cubic inches per pound = 2,133 in³
- 2,133 in³ ÷ 0.375 in. (3/8") = 5,688 in²
- 5,688 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 39.5 ft²
39.5 square feet is the coverage of a 5-gallon unit of Brush-On® 40 or 50 when applied 3/8" thick.
One-gallon Unit (18 lbs.) Coverage
- 18 lbs. x 23.7 cubic inches per pound = 426.6 in³
- 426.6 in³ ÷ 0.375 in. (3/8") = 1137.6 in²
- 1137.6 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 7.9 ft²
7.9 square feet is the coverage of a gallon unit of Brush-On® 40 or 50 applied 3/8" thick
How many square feet will one 5-gallon unit (90 lbs.) of Brush-On® 60 urethane rubber cover at 3/8" thickness?
- 90 lbs. x 23.5 cubic inches per pound = 2,115 in³
- 2,115 in³ ÷ 0.375 in. (3/8") = 5,640 in²
- 5,640 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 39.2 ft²
39.2 square feet is the coverage of a 5-gallon unit of Brush-On® 60 applied 3/8" thick.
One-gallon Unit (18 lbs.) Coverage
- 18 lbs. x 23.5 cubic inches per pound = 423 in³
- 423 in³ ÷ 0.375 in. (3/8") = 1,128 in²
- 1,128 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 7.8 ft²
7.8 square feet is the coverage of a gallon unit of Brush-On® 60 applied 3/8" thick.
How many square feet will one 5-gallon unit (55 lbs.) of Mold Max® STROKE cover at 3/8" thickness?
- 55 lbs. x 23.5 cubic inches per pound = 1,293 in³
- 1,293 in³ ÷ 0.375 in. (3/8") = 3,448 in²
- 3,448 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 24 ft²
24 square feet is the coverage of a 5-gallon unit of Mold Max® STROKE applied 3/8" thick.
One-Gallon Unit (11 lbs.) Coverage
- 11 lbs. x 23.5 cubic inches per pound = 259 in³
- 259 in³ ÷ 0.375 in. (3/8") = 691 in²
- 691 in² ÷ 144 in²/ft² (no. of square inches in a square foot) = 4.8 ft²
4.8 square feet is the coverage of a 1 gallon unit of Mold Max® STROKE applied 3/8" thick