Composites: Everything you didn’t know you needed to know…
Composite services are used in boat building, component construction and in the refit and repair of yachts; they are incredibly important as they offer flexibility, strength and lightweight production.
In the past, architects have been restricted on what materials they can use in their design work, typically turning to timber, steel, concrete, masonry and the like. In today’s modern age, composite services have revolutionised yacht refit and custom development offering greater freedom to designers to manufacture complex and precise shapes.
So, what are composite services?
Put simply, a composite is a product which is composed of more than one type of material to meet specific design needs.
Luke Hendy from Branagh Marine Composites, a specialist in the design and manufacture of carbon fibre equipment for superyachts explained, “Composites are combinations of fibres and resin materials in a definite proportion to create a component tailored to the desired specifications. While the resin allows the product to hold its composite shape, the fibres act as reinforcement and the two together make an extremely durable and lightweight product.
“The structural requirements, including the quantity of resin to fibre, are calculated by a structural engineer to ensure the correct performance of the part with extremely accurate results."
How do composite materials work?
When using composites in marine projects, two basic components are mixed to create a reinforcing fibre and polymer matrix.
To lay a basic understanding, composites start as a resin, such as polyester – the pour-able, spray-able thermosetting plastic that hardens after mixing with a chemical catalyst. If you tried to build a boat from polyester alone, you would be able to create virtually any shape or form, but it would be impossibly fragile.
Resin is therefore combined with fibres, usually glass (E-glass or S-glass), aramid or carbon in order to reinforce and strengthen it for purpose.
Hendy continued, "Composites have been around for many years and were once considered a very expensive option. However, this opinion has changed dramatically; technological advances in raw materials and in manufacturing processes have resulted in a significant drop in production costs making composites a much more affordable option."
Where are composites used?
Over the years, the boatbuilding industry has been a leading pioneer in the use of composite techniques; the first product using composites was a boat built in the 1930s; in the 1960s the marine industry was the largest user of these materials.
Boat builders have been building fiberglass boats for decades; but more recently, high-performance yachts have been taking advantage of advanced composites (which use high-strength fibres with more advanced epoxy resin systems, compared to older traditional GRP construction methods that use glass fibre and a polyester resin system.
It‘s surprising how many products are made of composites, from sailing boats, deck fittings, rudders, hulls, swim ladders, masts and passerelles, to top-end bicycles and motorcycles, laptops, tent poles, fishing rods, golf clubs, crash helmets, exhibition centres and towers most of which primarily use carbon fibre for its much higher strength to weight ratio.
Benefits of composite services
Composites now play a major part in many industries largely due to the fall in costs and the versatility and impressive properties of these materials. Some of the benefits include:
- More versatility in aesthetic parts, giving the ability to mould complex geometric shapes
- The ability to integrate different surface finishes
- Superior durability and less degradation
- Improved thermal insulation
- Longevity; composite structures are highly resistant to corrosion
- Lightweight and rigid components
- Rapid installation
How composites are used in the yachting industry
Advanced composites are becoming more important to the marine industry; the lightweight structure reduces the weight of the yacht, increasing operating efficiency and reducing fuel consumption. In addition, the advanced composites tend to be greener than general composites or alloys producing fewer emissions in the manufacturing process.
Branagh Marine Composites shared some inside knowledge on how composite services continue to change the yachting landscape:
The refit and repair industry can benefit hugely by using composites purely by reducing the impact to the vessel when making changes or installing new parts during a refit. The simplified installation costs mean less impact on other work, a good example is that there is no need for welding, which in turn means no disruption to the interior or underlying systems that are in danger of being damaged due to hot work.
The cost of finishing the parts is also dramatically reduced due to the accuracy of the build methods employed and the lack of filling, fairing and finishing to the surrounding areas compared with traditional welded metals, so depending on the work load this can equate to considerable savings in the overall cost of a refit or new build.
There are a good number of reasons why composites are fast becoming the material of choice in the yachting industry whenever and wherever possible. Either in new construction, refit and repair or simply when buying custom parts, such as a new swim ladder, gangway, tender fenders, deck furniture or any other component for small craft to superyachts.
Composites enable a 30 to 40% reduction in overall weight of a structure or component in contrast to traditional metals such as steel or Aluminium. This overall decrease in weight leads to a cascade of other benefits such as:
- Less maintenance
- No corrosion
- Lower operating costs
- Less greenhouse gas emissions
- Greater fuel efficiency
- Increased stability
- Increased working life and lower life time cost
- Lower installation and assembly costs
Disadvantages of composites
The most obvious disadvantage of using composites is the initial costs outlay involved in raw materials and increased production time compared to their metal counterparts. Glass fibres, carbon fibres, foam core materials and resins such as thermosets and thermoplastics can attract a higher price tag. Also, when it comes to the manufacture of composite parts, the tooling and capital costs are high compared to metals.
However, Luke from Branagh Marine Composites was keen to point out that, “The initial cost of the composite option is more expensive but, the savings over the life span of the product tip the balance very much in favour of composites.”