Adhesives versus welding for marine applications

Welding delivers proven strength and remains the established joining method for many metal structures. Rivets and mechanical fasteners also provide dependable, inspectable joints and can make future disassembly easier.

There are other marine applications where reaching automatically for a welder, drill or rivet gun can introduce unnecessary complications.

Drilling in marine applications creates holes that may need sealing and can produce local stress concentrations. Welding introduces heat, which can distort thinner materials, damage finished surfaces and restrict the combinations of materials that can be joined. Mechanical fasteners can add weight, require access from both sides and leave visible fixing points.

A correctly specified adhesive or tape can provide a different approach. Depending on the joint, these technologies can distribute stress across a wider area, join dissimilar materials, accommodate movement and create a clean finish without visible fixings.

Product selection, surface preparation, joint design and process control all affect the final result. The suitability of any adhesive or tape depends on the complete application. Load direction, joint geometry, substrate condition, temperature, saltwater exposure, UV, vibration, required service life and production timings must all be considered.

Structural adhesives or bonding tapes?

Liquid structural adhesives and high-performance bonding tapes solve different problems.

Marine Structural adhesives can provide high-strength bonds across metals, composites and plastics. Different chemistries offer varying levels of strength, flexibility, impact resistance, gap filling and environmental durability. They can be particularly useful where surfaces are uneven or where the joint needs a defined level of flexibility.

Bonding tapes provide a consistent bond-line thickness and immediate contact across the joint. They can support fast, clean assembly without the curing and dispensing stages associated with many liquid adhesives. Products such as 3M VHB tapes are already used across marine and transportation applications for attaching panels, trims and other components.

The right answer may also involve a combination of methods. An adhesive or tape can sometimes work alongside mechanical fasteners, allowing each technology to handle the loads and process requirements it is best suited to manage.

On 22 September, TECHSiL and 3M are taking to The Boating Stage at the Southampton International Boat Show for a practical discussion about adhesives, tapes, welding and riveting in modern marine construction. There will be multiple live demonstrations, expert insight from people who work with these technologies every day, and an honest look at where adhesives and tapes belong in marine manufacturing.