Materials and construction process
The quest to make our boats lighter and stronger resulted in our adopting and perfecting many of the techniques used to make the Volvo Ocean Class racers. We call this epoxy sandwich infusion process. This process consists of techniques as well as material choices so that we can consistently build a safe light weight structure. Not surprisingly, the epoxy sandwich infusion process results in a boat that will keep its value, strength and light weight because, unlike more traditional building techniques and materials, it is completely immune to water absorption.
Using female moulds a layer bi-directional basalt is used as the outside skin.
Then a layer of 20 mil (40 mil is used on the roof) AFC47 Divinycell structural foam is placed onto the layer. This special foam was developed by African Cats and is exclusive to our boats. It allows for a lighter and stronger structure than would normally be possible with the standard Divinycell products.
The foam is superior to core balsa which is traditionally used in light weight boats because it is lighter, will not absorb water, cannot rot and requires less resin to assemble.
Then a layer of 700 grammes basalt is placed on top of the structural foam to complete the sandwich. Twaron is also used on the inside of the hulls as an extra impact protection barrier; it has over 8 times the strength of glass against impact and is light weight.
The entire structure is vacuum bagged for 24 hours. This removes all the air from the layers and prepares it for the infusion of epoxy resin.
Epoxy resin is 30% stronger then polyester, watertight and won’t shrink. Since the structures don’t shrink there is no pre-release in the mould (the structure doesn’t shrink away from the sides) and this results in a smoother surface. There are no styrene emissions during the building process or thereafter and it is free of osmosis. This makes it safe for the environment, the boat builders and the customer.
Twaron aramid and Carbon
Additional Twaron aramid and Carbon are used throughout the boat where extra strength is required such as in the bulkheads, modules (mast support), keels, rudders, winch stands and the integral water and fuel tanks.
The boats are made in two pieces, the hulls and the deck. After the interior modules are placed in the hull, the top and bottom are joined together. Finally the structure is post cured for 8 hours @ 80 degrees centigrade. The result is an extremely strong lightweight structure which can easily deal with the forces developed in ocean sailing and does not absorb water.
Carbon: 15% weight reduction
An even lighter weight High-performance model is available, at extra cost, using bi-directional carbon cloth in place of the e-glass/basalt. Strength is actually improved while weight is reduced an additional 15 %.
The reduction in weight over traditional methods allows us to specify a higher payload. This flexibility in design makes the boat suitable for the performance sailor as well as the world voyager. Keep it light for racing and load it up for cruising while maintaining better performance than most of the cruising cats out on the water today.
A boat that won’t absorb water is a boat that will perform the same year in and year out. It is a boat that won’t weaken with time and will maintain resale value.
- Diesel and water tanks are integrated with the hulls which results in lighter weight and more strength as the tanks are part of the structure with Twaron and Carbon.
- Carbon reinforcements at all key structural areas.
One piece construction whenever possible.
Unlike most other catamarans the hulls, lower deck and cabin sole are built as one piece as is the deck itself. This results in a far stronger boat much in the same way as an integral body.