Choosing adhesive sealants for your boat

Choosing adhesive sealants for your boat

Getting the right type of adhesive sealant for your boat is critical, as an incorrectly finished repair can become dangerous if water can get into the structure. Before you start searching for the right product for your requirements, you should to look at the different types available and what they are best used for.


Image Credit

Sealants and adhesive sealants

It is essential to understand what the difference is between a sealant and an adhesive sealant. With an adhesive sealant, such as a metal bonding adhesive, you can seal fittings in addition to bonding the materials together.

When you are using a non-adhesive sealant, you will also need a screw, bolt or other fitting to form the waterproof seal. A standard sealant cannot be relied upon to hold materials together; instead, they are simply used to give you the necessary sealing properties.


Image Credit

Sealant types

The main types of sealant are silicone, hybrids, polyurethane and polysulphides. These sealants, such as those available from, can be used for the maintenance and repair of boats. With more and more people in the UK enjoying the core boating activities (up to 3.5 million in 2016), it is essential that you understand where these should be used.


Silicone adhesive sealants are an ideal choice for boating applications. They are resistant to heat and UV and provide effective insulation, making then efficient for gaskets; however, these factors can make it a weak adhesive and means it is not particularly suitable for using under the waterline.


Hybrid sealants are created by taking the best features of other products to form a more effective sealant that does not have any of the negative points. For instance, a hybrid could have the resistance to UV heat of silicone, combined with polyurethane’s strength, to form a good bond; however, this won’t be as strong as polyurethane alone.


Polyurethane is a good metal bonding adhesive that is UV resistant and is capable of being used under the waterline. A point to note is that this sealant is not compatible with plastic glazing, including acrylic Perspex.


This is a synthetic rubber that gives you an effective mechanical bond and offers resistance to fuel, oil and UV heat, along with protection from corrosion. It also has electrical insulating properties, with impact, shock, vibration and thermal change resistance.

Powered by