Densyl Mastic is a cold applied self-supporting mastic. It is a petrolatum compound containing inert siliceous fillers and vegetable fibers.

Uses: Densyl Mastic is used for sealing, filling and caulking applications where a protective, waterproof and non-setting mastic is required. It can be used to contour tank bases and profile irregular surfaces. It is applied prior to the tape application and generally used in conjunction with primer, Denso Petrolatum Tapes or Denso Bituminous Tapes.


• Excellent sealing properties • No VOCs • Will adhere to metal, PVC, polyethylene and concrete • Not effected by water, acids and salts • Easy application • Inert and environmentally stable • Minimal surface preparation (SSPC SP 2-3) • Meets AWWA C217 Standard.

Application: Prepare surfaces by removing all loose scale, rust or other foreign matter in accordance to SSPC SP2 “Hand Tool Cleaning” or SP3 “Power Tool Cleaning”. High pressure water wash of 3,000 – 7,000 psi (20.68 – 48.26 MPa) is also suitable. Apply a thin film of appropriate primer to the surface. Then, by hand application, mold the mastic to a rounded configuration to fill irregular shapes and reduce sharp edged surfaces.