3M Company 6500 Polyurethane Marine Adhesive Sealant

Product Description

The 3M COMPANY 6500 is a polyurethane marine adhesive and sealant designed for bonding and sealing applications in both above- and below-waterline environments. Supplied in a 1/10 gallon cartridge, it applies smoothly and evenly without sagging or flowing in vertical or horizontal seams. The formulation is tack-free in 48 hours and reaches a full cure in 5 to 7 days with no shrinkage. It bonds fiberglass and most woods, making it a go-to choice for marine maintenance and repair professionals who need a reliable, watertight seal that holds up to saltwater exposure and weathering.

This sealant is suited for marine construction and repair work on boats, docks, and related structures. It performs in both above-waterline and below-waterline seam applications. Common install scenarios include hull seams, deck fittings, through-hulls, and structural bonding where a flexible, watertight joint is required. The white color makes it appropriate for light-colored fiberglass and painted surfaces common in recreational and commercial marine applications.

Key Features

• Tack-free in 48 hours, fully cured in 5 to 7 days with no shrinkage
• Bonds fiberglass and most woods above and below the waterline
• Does not sag or flow in vertical or horizontal seams
• Excellent resistance to saltwater and weathering
• Smooth, even application from a standard 1/10 gallon cartridge
• White color for clean appearance on light-colored marine surfaces

Compatibility

Designed for bonding and sealing fiberglass and most wood substrates in marine environments, suitable for both above-waterline and below-waterline seam and joint applications.

Installation Notes

Application is typically performed by marine technicians or experienced boatyard professionals. Surfaces should be clean, dry, and free of grease or old sealant before application. A standard caulking gun is used with the 1/10 gallon cartridge format. Allow full cure of 5 to 7 days before submerging or loading the joint.

Technical Specifications

• Material: Polyurethane
• Color: White
• Container Size: 1/10 gallon cartridge
• Tack-Free Time: 48 hours
• Full Cure Time: 5 to 7 days
• Package Weight: 12 pounds
• Package Quantity: 12 per case

Standard Information

• Brand: 3M COMPANY
• Manufacturer Part Number: 6500