86 Fibered Trowel Mastic

86 Fibered Trowel Mastic

Available in: 5 gallon pail & 55 gallon drums

KARNAK 86 Fibered Trowel Mastic is manufactured from a blend of selected asphalts, fibers, stabilizers, fillers and solvents. KARNAK 86 Fibered Trowel Mastic is a heavy bodied product which dries to a tough, flexible and elastic protective coating. KARNAK 86 Fibered Trowel Mastic is highly resistant to the penetration of water and moisture over a wide range of temperature and service conditions. KARNAK 86 Fibered Trowel Mastic has excellent resistance to most acid, alkali, and salt spray solutions.



  • VOC: 295 g/L


  • ASTM D-4586 Type I, (Non-Asbestos)
  • Fed. Spec. SS-C-153 Type I (except Asbestos-Free)F)

Coverage Calculator

  • 5-6 Gallons per 100sf**


This is intended as a general guideline only, coverage can vary based on many factors.


KARNAK 86 Fibered Trowel Mastic is especially recommended for application as a protective coating for exterior masonry walls below grade and exterior face of interior walls (cavity wall construction), and as a dampproofing product for retaining walls, bridge abutments and steel panels. It is also used for the coating of interior faces of exterior masonry walls above grade, and for all back-up material for masonry, such as stone, brick or concrete. KARNAK 86 Fibered Trowel Mastic can be used for waterproofing when used in conjunction with a multi-membrane application.

Physical Properties

Weight per Gallon: 8.3 lbs.
Solids by Weight: 74%
Solids by Volume: 67 %
Color: Black
Dry Time: 24 to 48 hours
Service Temperature Range: 15°F to 160°F
Perm Rating: 0.25 perms

Preparation & Application

Surfaces must be clean, dry and free from oil, grease, release agents, laitance, dirt, dust and debris. All cracks and holes should be filled with KARNAK 86 Fibered Trowel Mastic prior to surface coating. If the surface is porous, it is recommended that KARNAK 108 Asphalt Primer be utilized to provide a firm  film base prior to application of KARNAK 86 Fibered Trowel Mastic.

KARNAK 86 Fibered Trowel Mastic is easily applied with a regular trowel. Using even strokes, a smooth uniform film can be obtained and provide adequate protection. Coating should be continuous and free of pinholes or holidays. Allow the film to cure for at least 24 to 48 hours prior to backfilling. Cure time  can be affected by the film thickness and the temperature. Care should be taken during backfilling, so as not to puncture or damage the coating. A  protection board is highly recommended to protect the film when backfilling. Backfilling should take place within 7 days.

A recommended coverage rate of 5 to 6 gallons per 100 square feet is desired for adequate protection. Application rates can vary depending upon the  surface to be covered.

Caution/Care of Tools

Do not use near open flame. Avoid breathing solvent and fumes and avoid prolonged contact with skin. Do not take internally. If swallowed, do not induce vomiting. Call a physician immediately. Keep out of reach of children. Keep container covered when not in use. Do not thin. Dispose of in an environmentally safe manner. Cover air intakes during application and while drying.

Tools and other equipment should be thoroughly cleaned with mineral spirits, taking necessary precautions when handling combustible materials.

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