Since Belzona’s inception in 1952, the company has been committed to pioneering innovative protective coatings and repair composites that meet the maintenance demands found across numerous application areas in a variety of different industries.

Built on this extensive experience and knowledge, the company is delighted to expand its product offering with a new high-performance structural epoxy adhesive: Belzona 7311.

This cold bonding adhesive is specially optimised for structural bonding applications subject to cyclic and repeated load where high mechanical strength, cleavage, shear and fatigue resistance are required. Thanks to its combination of high-performance properties and ease of use, Belzona 7311 is a valuable asset for any engineer looking for bonding solutions.

R&D Team Take Belzona’s Cold Bonding Technology to the Next Level

Belzona cold bonding technology has already been utilised in numerous application areas for decades. Although these systems provide effective bonding solutions, they are designed to be used across a wide range of application areas and therefore are not exclusively optimised for use as structural adhesives.

Given the clear demand for cold bonding solutions across a variety of application areas, the need for a polymeric solution that was exclusively designed for structural bonding applications emerged.

Commenting on the formulation process of the new product, one of the main developers behind Belzona 7311, Research and Development (R&D) Manager, Jason Horn, said: ‘Thanks to our historic success with Belzona systems in thousands of bonding applications over the years, we had access to a wealth of knowledge and experience when formulating our brand-new structural adhesive.’

He continued: ‘Building on this knowledge, we were able to really push the boundaries of what can be achieved with Belzona cold bonding technology. The result: a high-performance product that is perfectly formulated to meet the exact structural bonding requirements found across a wide variety of application and industry areas.’

What Are the Key Benefits of Belzona 7311?

- High resistance to cyclic fatigue and peel/cleavage forces
- Excellent adhesion to metallic substrates
- Suitable for dry or wet service between -30 °C (-22 °F) and 60 °C (140 °F)
- Cold-curing, solvent free material keeps application environment safe
- Easy to mix and apply without specialist tools

Alternative to Welding and Mechanical Fastenings/Fixings

While welding is a common bonding method used throughout many industries, it is not without its limitations. The welding procedure transmits the applied loads throughout the weld seams only, requires hot work permits and specialised equipment, it is not optimal for dissimilar metals, and it can often be difficult to install with complex shapes or where accessibility is poor. In addition, the heat generated by welding can result in heat affected zones and stressing of the welds unless heat treated, which can lead to increased corrosion.

Similarly, while mechanical fastenings or fixings are also popular jointing/assembly solutions, in some areas, these methods can prove to be problematic. For example, they can be susceptible to point loading, uneven stress distribution, metal distortion and tearing under heavy loads and, due to fatigue, can experience a loss of 

reliability, longevity, gapping or even failure. Also, like welding, these jointing/assembly methods can leave the application sites prone to corrosion and are often difficult to install in complex shapes.

All these problems can lead to increased downtime, asset replacement and increased financial expenditure.

Thanks to the comprehensive matrix of high-performance properties built into Belzona 7311, this epoxy structural toughened adhesive successfully bypasses these problems in the following ways: 

- Adhesive applied to cover the entire joint, resulting in uniform stress distribution and load transmission, reducing metal distortion under strain
- Good damping properties give high toughness and fatigue resistance
- Can accommodate complex shapes and be installed where accessibility is poor
- Minimal training required for application procedure
- No hot work or specialist equipment required
- Does not promote corrosion
- Lightweight and easy to apply, reducing costs and labour

Extensive Performance Data Allows Maintenance Teams to Perform Finite Element Analysis (FEA)

Having produced an extensive portfolio of mechanical and performance data from the development and testing of Belzona 7311, reliability and maintenance engineers can use this information to conduct finite element analysis (FEA) to design joints and bonded assemblies. 

it will be subjected to in use. This helps to provide demonstrable evidence that the epoxy technology will deliver the required levels of performance within its designated application environment.

Performance data used to perform finite element analysis (FEA) of a bonded bracket

Where Can Belzona 7311 be Used?

Belzona 7311 can be used in a variety of application areas including: equipment support brackets, handrails on steel substrates, plate bonding, vessel furniture; internal and external, staircases and ladders.

How is Belzona 7311 Applied?

2-part epoxy adhesive easy to mix and apply

Firstly, the substrate is thoroughly prepared by grit blasting to ensure a surface profile of 75 µm (3 mil) and cleaned to ISO 8501-1 Sa 2½ standard. Next, the required amounts of base and solidifier are mixed together at a ratio of 3:1 until a uniform material is produced, free of any streakiness. The system is then ready to be applied onto the application area using a short-bristled brush and Belzona applicator.

Base and solidifier mixed together to achieve a uniform material, free of any streakiness

Once applied, the system is then left to cure. To achieve full adhesive strength, the cure time can be as quick as 48 hours when the temperature is 20 °C (68 °F) and can be accelerated depending on the temperature of the environment.

The following table provides more information on the cure times required for different temperatures:

Curing times of structural adhesive, Belzona 7311

Please refer to the Belzona 7311 Instructions For Use (IFU) for further application information.

What Does This New Epoxy Structural Adhesive Mean for Asset Owners?

In general, epoxy adhesives tend to have less resistance to peeling and cleavage forces than to shear, tensile, and compressive loads. Belzona 7311 has been toughened to offer a combination of high mechanical adhesion strength and cleavage, shear, and fatigue resistance. Maintenance personnel and reliability engineers can now specify a Belzona structural adhesive which can be FEA-modeled and engineered to deliver a state-of-the-art solution to assets subject to cleavage, shear, and repeated loads.

In turn, this helps to keep facilities’ operations running as smoothly and efficiently as possible, as greater adhesive strength decreases the bonded area’s susceptibility to failure. Thus, investing in Belzona 7311 helps asset owners to mitigate the costs that can be incurred to not only repair or replace damaged assets, but also in terms of the lengthy periods of downtime that can ensue should a bonded area fail.  

With a competitive combination of mechanical strength, cleavage, shear and fatigue resistance, amongst other high-performance features, Belzona 7311 goes beyond the capabilities of conventional bonding methods and delivers a superior, industry-leading epoxy cold bonding solution.

Belzona 7311: a high-performance epoxy cold bonding solution

For more information on Belzona 7311, please click here to view the product video and click here to visit the product page.