Optimal Adhesives for Bonding FRP Fibre Reinforced Plastic in Boat Construction

Introduction

When building boats, especially those made with FRP (Fibre Reinforced Plastic) such as carbon fiber and other composites, choosing the right adhesive is crucial. Several adhesives are commonly used for performance bonding, and each has its advantages and challenges. This article explores the suitability of different adhesives for bonding FRP in boat construction and emphasizes the critical role of surface preparation.

Adhesives for Bonding FRP

Here are four adhesives that are frequently recommended for bonding FRP materials:

Hysol E120 HP

Hysol E120 HP is known for its honey-like viscosity, which allows it to bond to a wide variety of substrates including metals. This makes it a versatile option for general bonding needs. However, it may not offer the same level of elasticity or gap filling capability as other options.

ProSet ADV 175/276 and 176/276

The ProSet 176/276 is often referred to as a “super toughened” adhesive with excellent elasticity. Its Vaseline-like viscosity and thixotropic nature make it easy to apply, even on vertical surfaces. It adheres well to multiple surfaces and can effectively fill gaps.

Lord Chemical’s T21

The Lord T21 adhesive has a peanut-butter-like consistency, making it thixotropic and adept at gap filling. However, its harder cure and greater physical effort required (especially when cold) might make it less suitable for extensive work. Despite this, its excellent bonding capabilities to various substrates, including metals, make it a strong contender.

Surface Preparation: Ensuring Bonding Success

Surface preparation is the key to a successful bond, particularly with metals. Oxides on the surface of metals can form very quickly, and bonding to these oxides rather than the actual metal can lead to weaker bonds. Therefore, thorough preparation is necessary to ensure a strong and lasting bond.

Preparation Steps for Metals

Remove all machine oils, cleaning the surface with warm soapy water. Wire brush the metal surface using a Dremel tool to remove any leftover contaminants. Soak parts in an ultrasonic cleaner with a mild soap solution for 10-20 minutes. Dry the parts thoroughly using clean paper towels.

Preparation Steps for FRP

Thoroughly clean the surface with solvents and/or soap and water to remove any contaminants. Grind the surface to a clean, fresh state. Finish with a cleaning using acetone, MEK, or lacquer thinner to ensure a dust-free surface.

Conclusion

Choosing the right adhesive and ensuring proper surface preparation is essential for success in FRP boat construction. While each adhesive has its unique properties, ProSet 176/276 often stands out due to its excellent elasticity and ease of application. For critical applications where absolute perfection is required, like custom boarding ladders on mega yachts, the preparation steps are even more crucial to prevent any potential failures in the field.

Keywords: FRP glue, boat construction, adhesive selection