The leather seals in a hydraulically powered sealcoating machine’s piston pump require no daily upkeep. They typically pump at least 150,000 gallons of sealcoat before needing to be replaced, outlasting the rubber seals in less-expensive diaphragm-pump sealcoaters.
The higher pressure of hydraulic-powered piston pumps moves sealcoat 40% faster than diaphragm pumps. Because pistons are more powerful than the compressed air that powers diaphragm pumps, the design is ideal for thick material such as asphalt emulsions and modified sealers.
Sealants are a mixture of water, clay, sand, polymers and, depending on application, less than 20% of asphalt or refined coal tar. Pavement must be free of debris to ensure strong adhesion. A two-coat application requires 24 to 48 hours of curing before the surface can be opened to traffic.