Mainstay ML-72FS is a fast set, single-component blend of portland cement, microsilica, thermoplastic fiber, densifiers, admixtures, and other modifiers. Mainstay ML-72fs is fast-setting (approximately 15 minutes), which makes it ideally suited for filling large voids in manholes or concrete walls, reconstructing manhole inverts, and making repairs in pipes and pipe inverts. Mainstay ML-72FS produces excellent adhesion to properly prepared existing concrete, brick, or steel surfaces. Mainstay ML-72 product data PDF Download our product detail sheet (339 KB, opens in separate window).

Product Overview

Mortar Type

Portland cement and natural siliceous aggregates enhanced with microsilica, polypropylene fibers, and various additives


50 pound bag; special packaging available

Mix Water

Up to 3/4 gallons per bag


0.42 cubic feet per bag when mixed correctly

Compressive Strength

>8,000 pounds per square inch in 28 days (ASTM C-109)


0% after 28 days at 90% relative humidity (ASTM C-490)

Application Equipment

Contact us for information regarding the proper equipment to apply this product.