November 18, 2016 - General Transportation

Marine Sealants: Qualities, Applications, Technologies

According to Hexa Research, the global marine market was worth $6 billion in 2015 and is expected to see substantial growth in the coming years. This is due in large part to the following:

  • Increasing customer preference for sustainable products
  • Rapid growth of shipbuilding industry
  • Technological advancements

Let’s take a closer look at commercial and leisure marine sealants:

Marine Sealant Qualities 

Marine sealants provide a watertight and airtight seal between two or more surfaces on a boat. In addition to helping improve the boat’s aesthetics, durability and longevity, marine sealants offer noise deadening and vibration dampening qualities.

Additionally, it’s important for marine sealants to possess the following qualities:

  • Flexibility
  • Waterproof
  • UV, chemical and dirt resistance
  • Low tensile strength and high elongation

Marine sealants should also comply with volatile organic chemical (VOC) regulations to protect air quality and human health.

Marine Sealant Applications

Marine sealants for commercial and leisure boats are used in a variety of applications including:

  • Above and below water line sealing:
    • Above the water line sealants provide an important role in creating seaworthiness by bonding various substrates in applications like thru-hull fittings. For this especially, adhesion is important, but it’s important to note that the sealant cannot tear the gelcoat when the fitting is removed from the hull during normal maintenance.
    • Sealants for below the water line applications work well because they do not absorb water, which would lead to sealant degradation over time.

marine sealants

  • Deck to hull: Sealants for this application must have high tensile strength, good adhesion and moderate elongation, which is needed to allow the boat to flex when encountering elements like choppy waters and waves.
  • Window bonding: These sealants and adhesives play a critical role in ensuring a vessel’s water tightness by providing a strong, elastic bond. This feature helps keep water out of the boat and allows the window to move with the boat.

Marine Sealant Technologies

Marine sealants are commonly manufactured using silicone, polyurethane and SMP technologies.

  • Silicone: Silicone marine sealants are excellent insulators between dissimilar materials. Unaffected by most chemicals, these sealants offer superior elasticity when used for specific applications above the water line.
  • Polyurethane: Polyurethane marine sealants offer significant, permanent bonding strength and work well in hull bonding applications. They can offer excellent weathering and saltwater resistance.
  • SMP: SMP (silyl modified polyether) sealants for marine applications create a flexible bond between a variety of substrates including fiberglass and metal. These sealants exhibit great long term UV resistance, which is essential for the marine environment.

Stay tuned for upcoming blog posts about marine sealants. For more information on marine sealants, call 800-7-BOSTIK, or visit www.bostik.com/us.

Find out how your career can develop at Bostik. #workatbostik

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