The Hennes-Johnson HJ4520 mastic sprayer was built for modified bitumen, waterproofing emulsions, and elastomeric coatings that have to go on airless. At 4,500 PSI and powered by a 20 HP Honda engine, it has the pressure and volume to handle the heaviest pail-packaged coatings commercial roofing contractors work with. This is the sprayer only configuration without hose and gun.
Mastic and elastomeric coatings demand more from a pump than silicone does. They are heavier, they have more solids, and they will kill an undersized unit fast. The HJ4520 is sized for commercial production work where the material is thick, the square footage is large, and downtime is not acceptable. It runs on Honda power so parts and service are available anywhere.
West Side Supply and Rental carries the Hennes-Johnson HJ4520 for roofing contractors nationwide. Call us at 816-443-3004 before ordering to confirm the right configuration for your application.