Composite kayaks use epoxy bonding gel-coat

Nelo chose Crystic GC 253PA because of  its outstanding adhesion to epoxy resin.
Nelo chose Crystic GC 253PA because of its outstanding adhesion to epoxy resin.
Crystic® 253PA epoxy bonding gel-coat is tack free in less than 2 hours.
Crystic® 253PA epoxy bonding gel-coat is tack free in less than 2 hours.
The Epic ‘Touring’ model kayak is now much lighter than most touring kayaks.
The Epic ‘Touring’ model kayak is now much lighter than most touring kayaks.
The Nelo racing kayak used by the GB Olympic team.
The Nelo racing kayak used by the GB Olympic team.

Scot Bader says this technology is replacing a vinyl ester gel-coat for the hulls and decks of part of the range of kayaks Hangzhou Epic Boat Co and Nelo M.A.R. Kayaks Lda make for recreational touring, ocean and slalom racing. By making the switch to Crystic GC 253PA epoxy bonding gel-coat both companies have seen improvements in quality, weathering performance and manufacturing productivity.

The changeover by Hangzhou Epic Boat Co from using a vinyl ester gel-coat to a polyester epoxy bonding gel-coat was driven by two key factors:

  • improving product quality; and
  • reducing costs.    

In production, the vinyl ester gel-coat required both back surface preparation and a tiecoat to be applied prior to infusing the epoxy resin laminate structure. Significant productivity gains and cost savings have been achieved with Crystic GC 253PA as no back surface preparation or tiecoat are required. Overall de-mould times are also reduced as Crystic GC 253PA is tack free in under two hours.

The designs and composite technology used by Hangzhou Epic Boat Co, part of Epic Kayaks Inc, USA, originates from the development work done by the co founders of  Epic Kayaks, Greg Barton, a two times Olympic Gold Medalist and Oscar Chalupsky, 11 times World Molokai solo ocean racing champion. The epoxy kayaks are made by Hangzhou Epic Boat Co in its new purpose built factory in Zhejiang province, China, using Crystic GC 253PA polyester epoxy bonding spray gel-coat supplied by Scott Bader Asia Pacific. The new factory started production in early 2009.

More recently Nelo M.A.R. Kayaks Lda has also started using Crystic GC 253PA spray gel-coat in the production of a number of its high performance competition racing kayaks, which are mainly carbon fibre and Kevlar reinforced.

Nelo has built canoes and kayaks since 1978 and manufactured over 30 000 craft. It has a 5000 m2 factory located in Vila do Conde, near Porto, in northern Portugal and now claims to be the largest racing canoe and kayak manufacturer in the world. Nelo designs all its craft in-house. 

Decatlo Desportos E Composites, the official composites distributor for Scott Bader in Portugal, has been a key supplier to Nelo for over 20 years. A representative from Decatlo, who has worked closely with Nelo on many composites development projects over the years, comments:  

“They chose Crystic GC 253PA epoxy bonding spray gel-coat for several reasons, but the two most important aspects for Nelo were the outstanding adhesion to epoxy resin, which they see as ‘best in class’ and the consistent high quality of the Crystic gel-coat, with no noticeable colour variation between the epoxy bonding gelcoat batches supplied to them.”        

Spray trials by both companies with Crystic GC 253PA have successfully demonstrated it to be robust, sag resistant and easy to handle. Scott Bader claims that all Crystic epoxy bonding gel-coats in the range have significantly improved weathering performance compared with either a vinyl ester or epoxy gel-coat. As part of its product development, Scott Bader independently tests all its gel-coats for 12 months under extreme UV resistance and durability test conditions in Florida, USA.     

The Crystic Epoxy Bonding gel-coat range has brush, spray, low odour and fire retardant options. All are pre-accelerated, isophthalic gel-coats, which use a standard MEKP catalyst. They are 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.