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Major advancements in long fibre injection

News International-French

11 Feb 2011

Designed by Olympic Gold medallist and world solo Ocean Racing champion using the latest epoxy bonding gelcoat technology, these new kayaks exhibit improved weathering performance and significant manufacturing productivity gains.

(Published on February-March 2010 – JEC Magazine #55)


Epic Kayaks design and manufacture a range of epoxy resin-based composite kayaks for touring, surf ski racing and ICF racing. The designs and composite technology used were developed by the co-founders Greg Barton, two times Olympic Gold Medallist, and Oscar Chalupsky, eleven times World Molokai solo ocean racing champion. They use highperformance composite materials and the latest technology to build kayaks which are extremely light but strong, easy to handle and highly efficient in the water.


The epoxy kayaks made in their new purpose-built factory in China now use the polyester epoxy bonding spray gelcoat, Crystic® GC 253PA, supplied by Scott Bader Asia Pacific instead of a vinyl ester gelcoat. This had resulted in improved weathering performance and significant manufacturing productivity gains.



Hangzhou Epic Boat Co. Ltd., a whollyowned subsidiary of Epic Kayaks, Inc., started production in China in early 2009. Their 10,000 square meter custom-built factory, located in Zhejiang province, about 300 km from Shanghai, is equipped with temperature-controlled laminating rooms, high-capacity vacuum pumps and postcuring ovens. All craft are fully heat postcured to ensure maximum laminate strength.


The factory has been designed to ensure the best possible efficiency and quality control. It uses top-quality suppliers of highperformance composite materials for the different epoxy laminate constructions. A combination of woven fibreglass and Kevlar fabrics, carbon fibre, honeycomb pattern foam cores, or Nomex honeycomb cores are used depending on the model. The finished kayaks are mainly exported to the USA, Australia and Europe.


The changeover by Hangzhou Epic Boat Co. from using a vinyl ester gelcoat to a polyester epoxy bonding gelcoat was driven by two key factors: improving product quality and reducing costs.


Spray trials with Crystic® GC 253PA successfully demonstrated it to be robust, sag resistant and easy to handle. Quality improvements were achieved with the gelcoat due to its superior long-term UV weathering and gloss retention performance compared with the vinyl ester spray gelcoat. All Crystic® epoxy bonding gelcoats in the range have significantly improved weathering performance compared with either a vinyl ester or epoxy gelcoat. As part of its rigorous R&D product development, Scott Bader tests all its gelcoats under extreme 12-month UV resistance and durability conditions at a test site in Florida, USA. In production, the vinyl ester gelcoat required both back surface preparation and a tiecoat to be applied prior to infusing the epoxy resin laminate structure. Significant productivity gains and savings in both labour and raw material unit costs have been achieved by Hangzhou Epic Boat Co. as no back surface preparation or tiecoat is required. Overall demould times were further reduced as Crystic® GC 253PA is tack free in under two hours, which means the backup delay time is also shorter.



Another critical quality consideration is gelcoat adhesion. Rigorous adhesion tests on a variety of compatible epoxy resins were carried out and demonstrated that failure occurs internally within the laminate structure rather than at the gelcoat interface. Reliable performance in use has been proven for a number of years by other boat producers, such as Synthesize Yachts & Design Ltd., Hampshire, England.


The Crystic® epoxy bonding gelcoat range has brush, spray, low odour and fire retardant options. All are pre-accelerated, isophthalic gelcoats, which use a standard MEKP catalyst, designed for use in the wind energy, marine, building and transportation markets to provide a reliable, permanent bond with wet lay or prepreg epoxy resin systems.