3M 4200 Fast Cure Marine Sealant

• Medium strength marine bonding allows for disassembly
• Formulated for fast cure, providing rapid results
• Tack-free in 1 hour and typically cures in 24 hours
• Above and below the water line applications
• Flexible and durable adhesion withstands stress

Excellent for Applications Above and Below the Water Line 
3M™ Marine Adhesive Sealant Fast Cure 4200FC chemically reacts with moisture, delivering flexible bonds with good adhesion to wood, fiberglass, gelcoat, plastics and metals. This multi-purpose adhesive bonds dissimilar materials, forming a watertight, weather-resistant seal on joints and boat hardware above and below the waterline. The flexibility of 3M™ Marine Adhesive Sealant Fast Cure 4200FC (PDF, 443.47 Kb) allows for joint movement and stress caused by shock, vibration, swelling or shrinking. Permanently elastic, this medium strength sealant adheres to a wide variety of substrates and allows for disassembly of parts after prolonged use. Available in cartridge and sausage packs to meet your application needs. 

Recommended Applications 

• Fiberglass deck to hull
• Wood to fiberglass
• Portholes
• Deck fittings
• Rubrail attachment
• Sealing screwholes
• Stanchion supports

Designed to Endure Marine Environments 
3M™ Marine Adhesive Sealant Fast Cure 4200FC (PDF, 6.73 Mb) is a part of our broad range of adhesive sealants uniquely formulated for the marine market. Designed for reliable performance, 3M Marine Adhesive Sealant Fast Cure 4200FC provides the strength and flexibility that can meet the demands of many tough applications. 

Understanding Polyurethane Sealants 
Polyurethane sealants provide strong, flexible durable elastomeric bonds that seal against the elements. These sealants excel in challenging industrial, transportation and construction applications. Polyurethane sealants are available in a wide variety of Shore A hardness, open time and colors to meet many application needs. Choose a 3M Manual or Pneumatic Applicator for dispensing 3M adhesives sealant cartridges and 400ml/600ml sausage packs. 

Bringing Better Ideas to the Surface through Science and Innovation 
In our 3M Industrial Adhesives and Tapes Division, we apply the science of adhesion to deliver innovative solutions that improve the design and manufacturing processes of companies around the world. In the end, our technologies help customers like you deliver competitive products to the market faster and more efficiently. 

Click here for more information on 3M™ Adhesive Sealants. (PDF, 797.43 Kb) 

 

3M 4200 Fast Cure Marine Sealant is a versatile, high-performance adhesive and sealant made specifically for marine environments. Formulated to cure quickly, it creates a tough yet flexible bond that stands up to water, UV exposure, vibration, and weather—ideal for sealing joints, hardware, and through-hull fittings on boats and other watercraft.

Unlike permanent adhesives, 3M 4200 provides a strong, semi-permanent bond that can be disassembled if needed, making it perfect for applications where future maintenance or part replacement may be required. It adheres well to fiberglass, wood, metal, gelcoat, and many plastics.

The fast-cure formula significantly reduces downtime, allowing you to get back on the water sooner. Whether you're performing DIY boat repairs or professional installations, 3M 4200 delivers reliability, flexibility, and a watertight seal where it matters most.