How much material do I need for a repair?

1 gallon equals 128 ounces, which also equals 231 cubic inches. Therefore, figure the approximate cubic inches, and convert that to ounces. When dry silica sand is added to the product, you can increase your total volume by 150%. Example, 2 gallons of Spall material + 2 gallons of dry silica sand = approximately 3 gallons of mixed material. Please see volume charts for exact calculations.