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Mastix™ Butyl Tape

This versatile, trimmable, end-lap sealing tape joins metal to metal, and seals around windows, doors, roof vents, stacks, access doors and other penetration points. Non-staining and permanently flexible, Mastix stays in place with no melting or oozing, even in extreme heat.

Mastix™ Butyl Tape

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Unlike some tapes, Mastix combines superior performance with easy installation. It features a superior adhesive that keeps the product roll intact and prevents it from telescoping, even on hot days. Apply Mastix to a hot metal roofing panel, and it will stay put while you place the panel. You won’t experience oozing that causes panels to slide, making your installation harder.

3/32” x 3/8” x 45’: 16 rolls/carton, 30 carton/pallet
3/32” x ½” x 45’: 16 rolls/carton, 30 carton/pallet
3/32” x ¾” x 45’: 16 rolls/carton, 30 carton/pallet
3/32” x 1” x 45’: 12 rolls/carton, 30 carton/pallet
Chemical Name: Isobutylene
Chemical Family: Butyl Mixture
Health Hazard: 0-Minimal
Flammability Hazard: 0-Minimal
Reactivity Hazard: 0-Minimal
Volatile (WL)%: 0
Solubility in Water: Insoluble
Specific Gravity (H20=1): 1.59-1.64
Evaporation Rate: Not Applicable
Appearance: Soft, pliable gum
Color: Q-126 (off-white to gray), Q126BB (black), Q-126-10 (off-white to gray)
Odor: None
Fire Hazards
Flash Point: >400°F (204°C)
Method: Pensky Marten closed cup
Extinguishing Media: Dry chemical, carbon dioxide, foam, water
Special Fire-Fighting Procedures: Large quantities of water will extinguish. Do not enter confined space without proper protective equipment.
Hazardous Combustion Products: Carbon monoxide, carbon dioxide
Hazardous Identification

  • Based on data available to Marco Industries, none of the components in this product are considered hazardous according to OSHA Hazard communication Standard 29CFR 1910,1200.
  • The composition of this mixture is proprietary information. In the event of a medical emergency, compositional information will be provided to a physician or nurse.

How To Install

Mastix requires no tools for installation. It comes in an easy-to-handle roll and the adhesive is quickly exposed with a simple peel-back.

Step 1

Roll Mastix Butyl Tape out on through-fastened and standing seam panels, removing the release paper to expose adhesive.

Step 2

Position panel over Mastix.

Step 3

When positioned, press panel down on Mastix and fasten in place with QuikDrill™ or QuikGrip™ fasteners.

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