Black Polyurethane Construction Sealant – CRL M64BL (10.1 oz)

Description

Overview

The CRL M64BL Black Smooth Polyurethane Construction Sealant is engineered for demanding joint sealing applications in construction, glazing, and RV manufacturing. With a one-part, moisture curing formula and primerless adhesion, it delivers long-term flexibility, UV resistance, and excellent bond strength to common building substrates.

Key Features

• Primerless adhesion on most metals, masonry, glass, wood, and plastics
• Low modulus with +100% to -50% joint movement capability
• VOC compliant at only 9 g/L
• UV resistant and non-yellowing
• Service temperature range: -75°F to 300°F (-59°C to 149°C)
• Permanently flexible; will not harden with age
• Paintable after 2 hours (water-based paints)

Perfect For

• Sealing perimeter joints in windows, doors, and panels
• Storefront and curtain wall applications
• RV, trailer, and mobile home construction
• Galvanized ductwork assembly

For a weather-tight seal between your truck cab and camper or pass-through conversion, pair this sealant with our
Vinyl Insert Replacement and other Rubber Boot Seal products.

Specifications

Brand	CRL (C.R. Laurence)
Model / Part #	M64BL
Color	Black
Cartridge Size	10.1 fl oz (300 ml)
Weight	~1.2 lbs
Materials	Modified Polyurethane
Joint Movement	+100% / -50%
Service Temp	-75°F to 300°F
Standards	ASTM C920-98, TT-S-00230C, AAMA 808.3-92, USDA Approved
Shelf Life	12 Months

Installation / Setup

1. Ensure surfaces are clean, dry, and free of dust or contaminants.
2. Cut nozzle to desired bead size.
3. Apply using a standard cartridge caulking gun.
4. Tool the bead within 20–40 minutes.
5. Allow skin formation (~30 minutes), full cure rate of 1/8″ per day.
6. Paint (if desired) after 2 hours for water-based paints or after full cure for other paints.

What’s In the Box

• 1 × 10.1 fl oz cartridge (Black)

Care & Maintenance

• Store unopened cartridges in a cool, dry place.
• Use within 12 months of manufacture.

Safety & Compliance

• VOC compliant – qualifies for LEED credit
• Meets ASTM C920 and Federal TT-S-00230C
• USDA approved for food area use
• Prop 65 Warning – reproductive harm

FAQs

• Q: Is it paintable?
  A: Yes, with water-based paints after 2 hours, or after full cure for other types.
• Q: Can it be applied in cold weather?
  A: Yes, suitable for application above 0°F (-18°C).